diff --git a/src/db/db/db.pro b/src/db/db/db.pro
index df5648b48..35293190d 100644
--- a/src/db/db/db.pro
+++ b/src/db/db/db.pro
@@ -204,7 +204,6 @@ SOURCES = \
     gsiDeclDbNetlistCrossReference.cc \
     gsiDeclDbLayoutVsSchematic.cc \
     dbNetlistObject.cc \
-    dbD25TechnologyComponent.cc \
     gsiDeclDbTexts.cc \
     dbTexts.cc \
     dbDeepTexts.cc \
@@ -381,7 +380,6 @@ HEADERS = \
     dbLayoutVsSchematicFormatDefs.h \
     dbLayoutVsSchematic.h \
     dbNetlistObject.h \
-    dbD25TechnologyComponent.h \
     dbTexts.h \
     dbDeepTexts.h \
     dbAsIfFlatTexts.h \
diff --git a/src/db/db/dbCellVariants.cc b/src/db/db/dbCellVariants.cc
index 0126a75c3..5f36cc7b7 100644
--- a/src/db/db/dbCellVariants.cc
+++ b/src/db/db/dbCellVariants.cc
@@ -511,19 +511,52 @@ VariantsCollectorBase::create_var_instances_non_tl_invariant (db::Cell &in_cell,
     std::map<db::cell_index_type, std::map<db::ICplxTrans, db::cell_index_type> >::const_iterator f = var_table.find (i->object ().cell_index ());
     if (f == var_table.end ()) {
 
-       in_cell.insert (*i);
+      in_cell.insert (*i);
 
     } else {
 
       const std::map<db::ICplxTrans, db::cell_index_type> &vt = f->second;
 
-      for (db::CellInstArray::iterator ia = i->begin (); ! ia.at_end (); ++ia) {
+      bool need_explode = false;
+      bool first = true;
+      db::cell_index_type ci = 0;
+
+      for (db::CellInstArray::iterator ia = i->begin (); ! ia.at_end () && ! need_explode; ++ia) {
 
         db::ICplxTrans rt = mp_red->reduce (for_var * mp_red->reduce_trans (i->complex_trans (*ia)));
         std::map<db::ICplxTrans, db::cell_index_type>::const_iterator v = vt.find (rt);
         tl_assert (v != vt.end ());
 
-        in_cell.insert (db::CellInstArrayWithProperties (db::CellInstArray (db::CellInst (v->second), i->complex_trans (*ia)), i->properties_id ()));
+        if (first) {
+          ci = v->second;
+          first = false;
+        } else {
+          need_explode = (ci != v->second);
+        }
+
+      }
+
+      if (need_explode) {
+
+        for (db::CellInstArray::iterator ia = i->begin (); ! ia.at_end (); ++ia) {
+
+          db::ICplxTrans rt = mp_red->reduce (for_var * mp_red->reduce_trans (i->complex_trans (*ia)));
+          std::map<db::ICplxTrans, db::cell_index_type>::const_iterator v = vt.find (rt);
+          tl_assert (v != vt.end ());
+
+          in_cell.insert (db::CellInstArrayWithProperties (db::CellInstArray (db::CellInst (v->second), i->complex_trans (*ia)), i->properties_id ()));
+
+        }
+
+      } else if (ci != i->object ().cell_index ()) {
+
+        db::CellInstArray new_array = *i;
+        new_array.object () = db::CellInst (ci);
+        in_cell.insert (db::CellInstArrayWithProperties (new_array, i->properties_id ()));
+
+      } else {
+
+        in_cell.insert (*i);
 
       }
 
diff --git a/src/db/db/dbD25TechnologyComponent.cc b/src/db/db/dbD25TechnologyComponent.cc
deleted file mode 100644
index 9b421ed7e..000000000
--- a/src/db/db/dbD25TechnologyComponent.cc
+++ /dev/null
@@ -1,436 +0,0 @@
-
-/*
-
-  KLayout Layout Viewer
-  Copyright (C) 2006-2022 Matthias Koefferlein
-
-  This program is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-
-*/
-
-#include "dbD25TechnologyComponent.h"
-#include "tlClassRegistry.h"
-#include "tlString.h"
-
-namespace db
-{
-
-std::string d25_component_name ()
-{
-  return std::string ("d25");
-}
-
-std::string d25_description ()
-{
-  return tl::to_string (tr ("Z stack (2.5d)"));
-}
-
-// -----------------------------------------------------------------------------------------
-//  D25LayerInfo implementation
-
-D25LayerInfo::D25LayerInfo ()
-  : m_layer (), m_zstart (0.0), m_zstop (0.0)
-{
-  //  .. nothing yet ..
-}
-
-D25LayerInfo::~D25LayerInfo ()
-{
-  //  .. nothing yet ..
-}
-
-D25LayerInfo::D25LayerInfo (const D25LayerInfo &other)
-{
-  operator= (other);
-}
-
-D25LayerInfo &
-D25LayerInfo::operator= (const D25LayerInfo &other)
-{
-  if (this != &other) {
-    m_layer = other.m_layer;
-    m_zstart = other.m_zstart;
-    m_zstop = other.m_zstop;
-  }
-  return *this;
-}
-
-bool
-D25LayerInfo::operator== (const D25LayerInfo &other) const
-{
-  return fabs (m_zstart - other.m_zstart) < db::epsilon && fabs (m_zstop - other.m_zstop) < db::epsilon;
-}
-
-void
-D25LayerInfo::set_layer (const db::LayerProperties &l)
-{
-  m_layer = l;
-}
-
-void
-D25LayerInfo::set_layer_from_string (const std::string &l)
-{
-  db::LayerProperties lp;
-  tl::Extractor ex (l.c_str ());
-  try {
-    lp.read (ex);
-  } catch (tl::Exception &) {
-    //  ignore errors for now.
-  }
-  m_layer = lp;
-}
-
-std::string
-D25LayerInfo::layer_as_string () const
-{
-  return m_layer.to_string ();
-}
-
-void
-D25LayerInfo::set_zstart (double z0)
-{
-  m_zstart = z0;
-}
-
-void
-D25LayerInfo::set_zstop (double z1)
-{
-  m_zstop = z1;
-}
-
-// -----------------------------------------------------------------------------------
-//  D25TechnologyComponent implementation
-
-D25TechnologyComponent::D25TechnologyComponent ()
-  : db::TechnologyComponent (d25_component_name (), d25_description ())
-{
-  //  provide some explanation for the initialization
-  m_src =
-    "# Provide z stack information here\n"
-    "#\n"
-    "# Each line is one layer. The specification consists of a layer specification, a colon and arguments.\n"
-    "# The arguments are named (like \"x=...\") or in serial. Parameters are separated by comma or blanks.\n"
-    "# Named arguments are:\n"
-    "#\n"
-    "#   zstart   The lower z position of the extruded layer in µm\n"
-    "#   zstop    The upper z position of the extruded layer in µm\n"
-    "#   height   The height of the extruded layer in µm\n"
-    "#\n"
-    "# 'height', 'zstart' and 'zstop' can be used in any combination. If no value is given for 'zstart',\n"
-    "# the upper level of the previous layer will be used.\n"
-    "#\n"
-    "# If a single unnamed parameter is given, it corresponds to 'height'. Two parameters correspond to\n"
-    "# 'zstart' and 'zstop'.\n"
-    "#\n"
-    "# Examples:\n"
-    "#   1: 0.5 1.5                    # extrude layer 1/0 from 0.5 to 1.5 vertically\n"
-    "#   1/0: 0.5 1.5                  # same with explicit datatype\n"
-    "#   1: zstop=1.5, zstart=0.5      # same with named parameters\n"
-    "#   1: height=1.0, zstop=1.5      # same with z stop minus height\n"
-    "#   1: 1.0 zstop=1.5              # same with height as unnamed parameter\n"
-    "#\n"
-    "# VARIABLES\n"
-    "#\n"
-    "# You can declare variables with:\n"
-    "#   var name = value\n"
-    "#\n"
-    "# You can use variables inside numeric expressions.\n"
-    "# Example:\n"
-    "#   var hmetal = 0.48\n"
-    "#   7/0: 0.5 0.5+hmetal*2        # 2x thick metal\n"
-    "#\n"
-    "# You cannot use variables inside layer specifications currently.\n"
-    "#\n"
-    "# CONDITIONALS\n"
-    "#\n"
-    "# You can enable or disable branches of the table using 'if', 'else', 'elseif' and 'end':\n"
-    "# Example:\n"
-    "#   var thick_m1 = true\n"
-    "#   if thickm1\n"
-    "#     1: 0.5 1.5\n"
-    "#   else\n"
-    "#     1: 0.5 1.2\n"
-    "#   end\n"
-    "\n"
-  ;
-}
-
-D25TechnologyComponent::D25TechnologyComponent (const D25TechnologyComponent &d)
-  : db::TechnologyComponent (d25_component_name (), d25_description ())
-{
-  m_src = d.m_src;
-}
-
-D25TechnologyComponent::layers_type
-D25TechnologyComponent::compile_from_source () const
-{
-  layers_type layers;
-
-  int current_line = 0;
-
-  try {
-
-    tl::Eval eval;
-    std::vector<bool> conditional_stack;
-
-    std::vector<std::string> lines = tl::split (m_src, "\n");
-    for (std::vector<std::string>::const_iterator l = lines.begin (); l != lines.end (); ++l) {
-
-      ++current_line;
-
-      tl::Extractor ex (l->c_str ());
-
-      if (ex.test ("#")) {
-        //  ignore comments
-      } else if (ex.at_end ()) {
-        //  ignore empty lines
-
-      } else if (ex.test ("if")) {
-
-        tl::Expression x;
-        eval.parse (x, ex);
-        conditional_stack.push_back (x.execute ().to_bool ());
-
-        ex.expect_end ();
-
-      } else if (ex.test ("else")) {
-
-        if (conditional_stack.empty ()) {
-          throw tl::Exception (tl::to_string (tr ("'else' without 'if'")));
-        }
-
-        conditional_stack.back () = ! conditional_stack.back ();
-
-        ex.expect_end ();
-
-      } else if (ex.test ("end")) {
-
-        if (conditional_stack.empty ()) {
-          throw tl::Exception (tl::to_string (tr ("'end' without 'if'")));
-        }
-
-        conditional_stack.pop_back ();
-
-        ex.expect_end ();
-
-      } else if (ex.test ("elsif")) {
-
-        if (conditional_stack.empty ()) {
-          throw tl::Exception (tl::to_string (tr ("'elsif' without 'if'")));
-        }
-
-        tl::Expression x;
-        eval.parse (x, ex);
-        conditional_stack.back () = x.execute ().to_bool ();
-
-        ex.expect_end ();
-
-      } else if (! conditional_stack.empty () && ! conditional_stack.back ()) {
-
-        continue;
-
-      } else if (ex.test ("var")) {
-
-        std::string n;
-        ex.read_name (n);
-
-        ex.expect ("=");
-
-        tl::Expression x;
-        eval.parse (x, ex);
-        eval.set_var (n, x.execute ());
-
-        ex.expect_end ();
-
-      } else if (ex.test ("print")) {
-
-        tl::Expression x;
-        eval.parse (x, ex);
-        ex.expect_end ();
-
-        tl::info << x.execute ().to_string ();
-
-      } else if (ex.test ("error")) {
-
-        tl::Expression x;
-        eval.parse (x, ex);
-        ex.expect_end ();
-
-        throw tl::Exception (x.execute ().to_string ());
-
-      } else {
-
-        db::D25LayerInfo info;
-        if (! layers.empty ()) {
-          info.set_zstart (layers.back ().zstop ());
-          info.set_zstop (layers.back ().zstop ());
-        }
-
-        tl::Variant z0, z1, h;
-        std::vector<double> args;
-
-        db::LayerProperties lp;
-        lp.read (ex);
-        info.set_layer (lp);
-
-        ex.expect (":");
-
-        while (! ex.at_end ()) {
-
-          if (ex.test ("#")) {
-            break;
-          }
-
-          tl::Expression pvx;
-
-          std::string pn;
-          if (ex.try_read_name (pn)) {
-            ex.expect ("=");
-            eval.parse (pvx, ex);
-          } else {
-            eval.parse (pvx, ex);
-          }
-
-          double pv = pvx.execute ().to_double ();
-
-          ex.test (",");
-
-          if (pn.empty ()) {
-            args.push_back (pv);
-          } else if (pn == "zstart") {
-            z0 = pv;
-          } else if (pn == "zstop") {
-            z1 = pv;
-          } else if (pn == "height") {
-            h = pv;
-          } else {
-            throw tl::Exception (tl::to_string (tr ("Invalid parameter name: ")) + pn);
-          }
-
-        }
-
-        if (args.size () == 0) {
-          if (z0.is_nil () && z1.is_nil ()) {
-            if (! h.is_nil ()) {
-              info.set_zstop (info.zstop () + h.to_double ());
-            }
-          } else if (z0.is_nil ()) {
-            info.set_zstop (z1.to_double ());
-            if (! h.is_nil ()) {
-              info.set_zstart (info.zstop () - h.to_double ());
-            }
-          } else if (z1.is_nil ()) {
-            info.set_zstart (z0.to_double ());
-            if (! h.is_nil ()) {
-              info.set_zstop (info.zstart () + h.to_double ());
-            }
-          } else {
-            info.set_zstart (z0.to_double ());
-            info.set_zstop (z1.to_double ());
-          }
-        } else if (args.size () == 1) {
-          if (! h.is_nil ()) {
-            if (! z0.is_nil ()) {
-              throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstart already given")));
-            }
-            if (! z1.is_nil ()) {
-              throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstop implicitly given")));
-            }
-            info.set_zstart (args[0]);
-            info.set_zstop (args[0] + h.to_double ());
-          } else {
-            if (! z1.is_nil ()) {
-              throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstop implicitly given")));
-            }
-            info.set_zstop ((! z0.is_nil () ? z0.to_double () : info.zstart ()) + args[0]);
-          }
-        } else if (args.size () == 2) {
-          if (! z0.is_nil ()) {
-            throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstart already given")));
-          }
-          if (! z1.is_nil ()) {
-            throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstop already given")));
-          }
-          if (! h.is_nil ()) {
-            throw tl::Exception (tl::to_string (tr ("Redundant parameters: height implicitly given")));
-          }
-          info.set_zstart (args[0]);
-          info.set_zstop (args[1]);
-        } else {
-          throw tl::Exception (tl::to_string (tr ("Too many parameters (max 2)")));
-        }
-
-        layers.push_back (info);
-
-      }
-
-    }
-
-    if (! conditional_stack.empty ()) {
-      throw tl::Exception (tl::to_string (tr ("'if', 'else' or 'elsif' without matching 'end'")));
-    }
-
-  } catch (tl::Exception &ex) {
-    throw tl::Exception (ex.msg () + tl::sprintf (tl::to_string (tr (" in line %d")), current_line));
-  }
-
-  return layers;
-}
-
-std::string
-D25TechnologyComponent::to_string () const
-{
-  layers_type layers = compile_from_source ();
-  std::string res;
-
-  for (layers_type::const_iterator i = layers.begin (); i != layers.end (); ++i) {
-    if (! res.empty ()) {
-      res += "\n";
-    }
-    res += i->layer ().to_string () + ": zstart=" + tl::to_string (i->zstart ()) + ", zstop=" + tl::to_string (i->zstop ());
-  }
-
-  return res;
-}
-
-// -----------------------------------------------------------------------------------
-//  D25TechnologyComponent technology component registration
-
-class D25TechnologyComponentProvider
-  : public db::TechnologyComponentProvider
-{
-public:
-  D25TechnologyComponentProvider ()
-    : db::TechnologyComponentProvider ()
-  {
-    //  .. nothing yet ..
-  }
-
-  virtual db::TechnologyComponent *create_component () const
-  {
-    return new D25TechnologyComponent ();
-  }
-
-  virtual tl::XMLElementBase *xml_element () const
-  {
-    return new db::TechnologyComponentXMLElement<D25TechnologyComponent> (d25_component_name (),
-      tl::make_member (&D25TechnologyComponent::src, &D25TechnologyComponent::set_src, "src")
-    );
-  }
-};
-
-static tl::RegisteredClass<db::TechnologyComponentProvider> tc_decl (new D25TechnologyComponentProvider (), 3100, d25_component_name ().c_str ());
-
-}
diff --git a/src/db/db/dbD25TechnologyComponent.h b/src/db/db/dbD25TechnologyComponent.h
deleted file mode 100644
index db38b3124..000000000
--- a/src/db/db/dbD25TechnologyComponent.h
+++ /dev/null
@@ -1,106 +0,0 @@
-
-/*
-
-  KLayout Layout Viewer
-  Copyright (C) 2006-2022 Matthias Koefferlein
-
-  This program is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-
-*/
-
-#ifndef HDR_dbD25TechnologyComponent
-#define HDR_dbD25TechnologyComponent
-
-#include "dbTechnology.h"
-#include "dbLayerProperties.h"
-
-namespace db
-{
-
-class DB_PUBLIC D25LayerInfo
-{
-public:
-  D25LayerInfo ();
-  ~D25LayerInfo ();
-  D25LayerInfo (const D25LayerInfo &other);
-  D25LayerInfo &operator= (const D25LayerInfo &other);
-
-  bool operator== (const D25LayerInfo &other) const;
-
-  const db::LayerProperties &layer () const
-  {
-    return m_layer;
-  }
-
-  void set_layer_from_string (const std::string &l);
-  std::string layer_as_string () const;
-
-  void set_layer (const db::LayerProperties &l);
-
-  double zstart () const
-  {
-    return m_zstart;
-  }
-
-  void set_zstart (double z0);
-
-  double zstop () const
-  {
-    return m_zstop;
-  }
-
-  void set_zstop (double z1);
-
-private:
-  db::LayerProperties m_layer;
-  double m_zstart, m_zstop;
-};
-
-class DB_PUBLIC D25TechnologyComponent
-  : public db::TechnologyComponent
-{
-public:
-  D25TechnologyComponent ();
-  D25TechnologyComponent (const D25TechnologyComponent &d);
-
-  typedef std::list<D25LayerInfo> layers_type;
-
-  layers_type compile_from_source () const;
-
-  const std::string &src () const
-  {
-    return m_src;
-  }
-
-  //  for persistency only, use "compile_from_source" to read from a source string
-  void set_src (const std::string &s)
-  {
-    m_src = s;
-  }
-
-  std::string to_string () const;
-
-  db::TechnologyComponent *clone () const
-  {
-    return new D25TechnologyComponent (*this);
-  }
-
-private:
-  std::string m_src;
-};
-
-}
-
-#endif
diff --git a/src/db/db/dbHierProcessor.cc b/src/db/db/dbHierProcessor.cc
index 3c9d1215e..a54b9676f 100644
--- a/src/db/db/dbHierProcessor.cc
+++ b/src/db/db/dbHierProcessor.cc
@@ -1063,11 +1063,6 @@ private:
   void
   collect_instance_interactions (const db::CellInstArray *inst1, const db::CellInstArray *inst2)
   {
-#if 0
-printf("@@@ check instance interactions %s (#%d, %s) <-> %s (#%d, %s)\n",
-    mp_subject_layout->cell_name (inst1->object ().cell_index ()), int (inst1->size ()), (inst1->bbox(db::box_convert<db::CellInst> (*mp_subject_layout)).to_string()).c_str(),
-    mp_intruder_layout->cell_name (inst2->object ().cell_index ()), int (inst2->size ()), (inst2->bbox(db::box_convert<db::CellInst> (*mp_intruder_layout)).to_string()).c_str()); // @@@
-#endif
     //  TODO: this algorithm is not in particular effective for identical arrays
 
     const db::Cell &cell1 = mp_subject_layout->cell (inst1->object ().cell_index ());
@@ -1076,9 +1071,6 @@ printf("@@@ check instance interactions %s (#%d, %s) <-> %s (#%d, %s)\n",
 
     std::unordered_map<db::ICplxTrans, std::list<std::pair<db::cell_index_type, db::ICplxTrans> > > interactions_cache;
 
-#if 0
-printf("@@@  -> #%d\n", int(inst1->size()));
-#endif
     for (db::CellInstArray::iterator n = inst1->begin (); ! n.at_end (); ++n) {
 
       db::ICplxTrans tn1 = inst1->complex_trans (*n);
@@ -1482,9 +1474,6 @@ void local_processor<TS, TI, TR>::compute_contexts (local_processor_contexts<TS,
                                                     const typename local_processor_cell_contexts<TS, TI, TR>::context_key_type &intruders,
                                                     db::Coord dist) const
 {
-#if 0 // @@@
-printf("@@@ --- compute_contexts (%s @ %s)\n", mp_subject_layout->cell_name (subject_cell->cell_index ()), subject_cell_inst.to_string().c_str()); fflush(stdout);
-#endif
   CRONOLOGY_COLLECTION_BRACKET(event_compute_contexts)
 
   if (tl::verbosity () >= m_base_verbosity + 20) {
diff --git a/src/db/db/dbLayoutDiff.cc b/src/db/db/dbLayoutDiff.cc
index e57cd0240..e7940a24b 100644
--- a/src/db/db/dbLayoutDiff.cc
+++ b/src/db/db/dbLayoutDiff.cc
@@ -287,6 +287,32 @@ private:
   db::Coord m_tolerance;
 };
 
+/**
+ *  @brief A fuzzy compare operator for edge pairs
+ *  Compares two edge pair objects applying a tolerance between them. The tolerance is the allowed deviation
+ *  of points in database units.
+ */
+struct EdgePairCompareOpWithTolerance
+{
+  EdgePairCompareOpWithTolerance (db::Coord tolerance)
+    : m_ec (tolerance)
+  { }
+
+  bool operator() (const db::EdgePair &a, const db::EdgePair &b) const
+  {
+    if (m_ec (a.first (), b.first ())) {
+      return true;
+    } else if (m_ec (b.first (), a.first ())) {
+      return false;
+    } else {
+      return m_ec (a.second (), b.second ());
+    }
+  }
+
+private:
+  EdgeCompareOpWithTolerance m_ec;
+};
+
 /**
  *  @brief A fuzzy compare operator for boxes
  *  Compares two box objects applying a tolerance between them. The tolerance is the allowed deviation
@@ -492,6 +518,12 @@ make_edge_compare_func (db::Coord tolerance)
   return pair_compare_func<db::Edge, db::properties_id_type, EdgeCompareOpWithTolerance, std_compare_func<db::properties_id_type> > (EdgeCompareOpWithTolerance (tolerance), std_compare_func<db::properties_id_type> ());
 }
 
+pair_compare_func<db::EdgePair, db::properties_id_type, EdgePairCompareOpWithTolerance, std_compare_func<db::properties_id_type> >
+make_edge_pair_compare_func (db::Coord tolerance)
+{
+  return pair_compare_func<db::EdgePair, db::properties_id_type, EdgePairCompareOpWithTolerance, std_compare_func<db::properties_id_type> > (EdgePairCompareOpWithTolerance (tolerance), std_compare_func<db::properties_id_type> ());
+}
+
 pair_compare_func<db::Box, db::properties_id_type, BoxCompareOpWithTolerance, std_compare_func<db::properties_id_type> >
 make_box_compare_func (db::Coord tolerance)
 {
@@ -540,6 +572,21 @@ collect_edges (const db::Layout & /*l*/, const db::Cell *c, unsigned int layer,
   }
 }
 
+static void
+collect_edge_pairs (const db::Layout & /*l*/, const db::Cell *c, unsigned int layer, unsigned int flags, std::vector< std::pair<db::EdgePair, db::properties_id_type> > &shapes, PropertyMapper &pn)
+{
+  shapes.clear ();
+
+  for (db::ShapeIterator s = c->shapes (layer).begin (db::ShapeIterator::EdgePairs); !s.at_end (); ++s) {
+    db::properties_id_type prop_id = 0;
+    if (! (flags & layout_diff::f_no_properties)) {
+      prop_id = pn (s->prop_id ());
+    }
+    shapes.push_back (std::make_pair (db::EdgePair (), prop_id));
+    s->edge_pair (shapes.back ().first);
+  }
+}
+
 static void
 collect_boxes (const db::Layout &, const db::Cell *c, unsigned int layer, unsigned int flags, std::vector< std::pair<db::Box, db::properties_id_type> > &shapes, PropertyMapper &pn)
 {
@@ -828,6 +875,8 @@ do_compare_layouts (const db::Layout &a, const db::Cell *top_a, const db::Layout
   std::vector <std::pair <db::Box, db::properties_id_type> > boxes_b;
   std::vector <std::pair <db::Edge, db::properties_id_type> > edges_a;
   std::vector <std::pair <db::Edge, db::properties_id_type> > edges_b;
+  std::vector <std::pair <db::EdgePair, db::properties_id_type> > edge_pairs_a;
+  std::vector <std::pair <db::EdgePair, db::properties_id_type> > edge_pairs_b;
 
   for (unsigned int cci = 0; cci < common_cells.size (); ++cci) {
 
@@ -1053,6 +1102,31 @@ do_compare_layouts (const db::Layout &a, const db::Cell *top_a, const db::Layout
         r.end_edge_differences ();
       }
 
+      //  compare edge pairs
+
+      edge_pairs_a.clear();
+      edge_pairs_b.clear();
+      if (is_valid_a) {
+        collect_edge_pairs (a, cell_a, layer_a, flags, edge_pairs_a, prop_normalize_a);
+      }
+      if (is_valid_b) {
+        collect_edge_pairs (b, cell_b, layer_b, flags, edge_pairs_b, prop_normalize_b);
+      }
+
+      reduce (edge_pairs_a, edge_pairs_b, make_edge_pair_compare_func (tolerance), tolerance > 0);
+
+      if (!edge_pairs_a.empty () || !edge_pairs_b.empty ()) {
+        differs = true;
+        if (flags & layout_diff::f_silent) {
+          return false;
+        }
+        r.begin_edge_pair_differences ();
+        if (verbose) {
+          r.detailed_diff (n.properties_repository (), edge_pairs_a, edge_pairs_b);
+        }
+        r.end_edge_pair_differences ();
+      }
+
       r.end_layer ();
 
     }
@@ -1130,6 +1204,9 @@ public:
   void begin_edge_differences ();
   void detailed_diff (const db::PropertiesRepository &pr, const std::vector <std::pair <db::Edge, db::properties_id_type> > &a, const std::vector <std::pair <db::Edge, db::properties_id_type> > &b);
   void end_edge_differences ();
+  void begin_edge_pair_differences ();
+  void detailed_diff (const db::PropertiesRepository &pr, const std::vector <std::pair <db::EdgePair, db::properties_id_type> > &a, const std::vector <std::pair <db::EdgePair, db::properties_id_type> > &b);
+  void end_edge_pair_differences ();
   void begin_text_differences ();
   void detailed_diff (const db::PropertiesRepository &pr, const std::vector <std::pair <db::Text, db::properties_id_type> > &a, const std::vector <std::pair <db::Text, db::properties_id_type> > &b);
   void end_text_differences ();
@@ -1525,6 +1602,34 @@ PrintingDifferenceReceiver::end_edge_differences ()
 {
 }
 
+void
+PrintingDifferenceReceiver::begin_edge_pair_differences ()
+{
+  try {
+    enough (tl::error) << "Edge pairs differ for layer " << m_layer.to_string () << " in cell " << m_cellname;
+  } catch (tl::CancelException &) {
+    //  ignore cancel exceptions
+  }
+}
+
+void
+PrintingDifferenceReceiver::detailed_diff (const db::PropertiesRepository &pr, const std::vector <std::pair <db::EdgePair, db::properties_id_type> > &a, const std::vector <std::pair <db::EdgePair, db::properties_id_type> > &b)
+{
+  try {
+    enough (tl::info) << "Not in b but in a:";
+    print_diffs (pr, a, b);
+    enough (tl::info) << "Not in a but in b:";
+    print_diffs (pr, b, a);
+  } catch (tl::CancelException &) {
+    //  ignore cancel exceptions
+  }
+}
+
+void
+PrintingDifferenceReceiver::end_edge_pair_differences ()
+{
+}
+
 void
 PrintingDifferenceReceiver::begin_text_differences ()
 {
diff --git a/src/db/db/dbLayoutDiff.h b/src/db/db/dbLayoutDiff.h
index ed0e01e0b..4482c5009 100644
--- a/src/db/db/dbLayoutDiff.h
+++ b/src/db/db/dbLayoutDiff.h
@@ -119,6 +119,9 @@ public:
   virtual void begin_edge_differences () { }
   virtual void detailed_diff (const db::PropertiesRepository & /*pr*/, const std::vector <std::pair <db::Edge, db::properties_id_type> > & /*a*/, const std::vector <std::pair <db::Edge, db::properties_id_type> > & /*b*/) { }
   virtual void end_edge_differences () { }
+  virtual void begin_edge_pair_differences () { }
+  virtual void detailed_diff (const db::PropertiesRepository & /*pr*/, const std::vector <std::pair <db::EdgePair, db::properties_id_type> > & /*a*/, const std::vector <std::pair <db::EdgePair, db::properties_id_type> > & /*b*/) { }
+  virtual void end_edge_pair_differences () { }
   virtual void begin_text_differences () { }
   virtual void detailed_diff (const db::PropertiesRepository & /*pr*/, const std::vector <std::pair <db::Text, db::properties_id_type> > & /*a*/, const std::vector <std::pair <db::Text, db::properties_id_type> > & /*b*/) { }
   virtual void end_text_differences () { }
diff --git a/src/db/db/dbLayoutUtils.cc b/src/db/db/dbLayoutUtils.cc
index 3f18ff33a..dea4ab705 100644
--- a/src/db/db/dbLayoutUtils.cc
+++ b/src/db/db/dbLayoutUtils.cc
@@ -25,6 +25,7 @@
 #include "dbCellVariants.h"
 #include "dbPolygonTools.h"
 #include "tlProgress.h"
+#include "tlTimer.h"
 
 namespace db
 {
@@ -436,9 +437,38 @@ ContextCache::find_layout_context (db::cell_index_type from, db::cell_index_type
 // ------------------------------------------------------------
 //  Scale and snap a layout
 
+static void
+scale_and_snap_cell_instance (db::CellInstArray &ci, const db::ICplxTrans &tr, const db::ICplxTrans &trinv, const db::Vector &delta, db::Coord g, db::Coord m, db::Coord d)
+{
+  db::Trans ti (ci.front ());
+
+  db::Vector ti_disp = ti.disp ();
+  ti_disp.transform (tr);
+  ti_disp = scaled_and_snapped_vector (ti_disp, g, m, d, delta.x (), g, m, d, delta.y ());
+  ti_disp.transform (trinv);
+
+  ci.move (ti_disp - ti.disp ());
+}
+
+static db::Edge
+scaled_and_snapped_edge (const db::Edge &e, db::Coord g, db::Coord m, db::Coord d, db::Coord ox, db::Coord oy)
+{
+  int64_t dg = int64_t (g) * int64_t (d);
+
+  int64_t x1 = snap_to_grid (int64_t (e.p1 ().x ()) * m + int64_t (ox), dg) / int64_t (d);
+  int64_t y1 = snap_to_grid (int64_t (e.p1 ().y ()) * m + int64_t (oy), dg) / int64_t (d);
+
+  int64_t x2 = snap_to_grid (int64_t (e.p2 ().x ()) * m + int64_t (ox), dg) / int64_t (d);
+  int64_t y2 = snap_to_grid (int64_t (e.p2 ().y ()) * m + int64_t (oy), dg) / int64_t (d);
+
+  return db::Edge (db::Point (x1, y1), db::Point (x2, y2));
+}
+
 void
 scale_and_snap (db::Layout &layout, db::Cell &cell, db::Coord g, db::Coord m, db::Coord d)
 {
+  tl::SelfTimer timer (tl::verbosity () >= 31, tl::to_string (tr ("scale_and_snap")));
+
   if (g < 0) {
     throw tl::Exception (tl::to_string (tr ("Snapping requires a positive grid value")));
   }
@@ -453,8 +483,11 @@ scale_and_snap (db::Layout &layout, db::Cell &cell, db::Coord g, db::Coord m, db
 
   db::cell_variants_collector<db::ScaleAndGridReducer> vars (db::ScaleAndGridReducer (g, m, d));
 
-  vars.collect (layout, cell);
-  vars.separate_variants (layout, cell);
+  {
+    tl::SelfTimer timer1 (tl::verbosity () >= 41, tl::to_string (tr ("scale_and_snap: variant formation")));
+    vars.collect (layout, cell);
+    vars.separate_variants (layout, cell);
+  }
 
   std::set<db::cell_index_type> called_cells;
   cell.collect_called_cells (called_cells);
@@ -463,9 +496,10 @@ scale_and_snap (db::Layout &layout, db::Cell &cell, db::Coord g, db::Coord m, db
   db::LayoutLocker layout_locker (&layout);
   layout.update ();
 
-  std::vector<db::Point> heap;
+  tl::SelfTimer timer2 (tl::verbosity () >= 41, tl::to_string (tr ("scale_and_snap: snapping and scaling")));
 
-  unsigned int work_layer = layout.insert_layer ();
+  std::vector<db::Point> heap;
+  std::vector<db::Vector> iterated_array_vectors;
 
   for (db::Layout::iterator c = layout.begin (); c != layout.end (); ++c) {
 
@@ -486,7 +520,7 @@ scale_and_snap (db::Layout &layout, db::Cell &cell, db::Coord g, db::Coord m, db
     for (db::Layout::layer_iterator l = layout.begin_layers (); l != layout.end_layers (); ++l) {
 
       db::Shapes &s = c->shapes ((*l).first);
-      db::Shapes &out = c->shapes (work_layer);
+      db::Shapes new_shapes (layout.is_editable ());
 
       for (db::Shapes::shape_iterator si = s.begin (db::ShapeIterator::Polygons | db::ShapeIterator::Paths | db::ShapeIterator::Boxes); ! si.at_end (); ++si) {
 
@@ -495,7 +529,20 @@ scale_and_snap (db::Layout &layout, db::Cell &cell, db::Coord g, db::Coord m, db
         poly.transform (tr);
         poly = scaled_and_snapped_polygon (poly, g, m, d, tr_disp.x (), g, m, d, tr_disp.y (), heap);
         poly.transform (trinv);
-        out.insert (poly);
+
+        if (si->is_box () && poly.is_box ()) {
+          if (si->has_prop_id ()) {
+            new_shapes.insert (db::BoxWithProperties (poly.box (), si->prop_id ()));
+          } else {
+            new_shapes.insert (poly.box ());
+          }
+        } else {
+          if (si->has_prop_id ()) {
+            new_shapes.insert (db::PolygonWithProperties (poly, si->prop_id ()));
+          } else {
+            new_shapes.insert (poly);
+          }
+        }
 
       }
 
@@ -506,48 +553,94 @@ scale_and_snap (db::Layout &layout, db::Cell &cell, db::Coord g, db::Coord m, db
         text.transform (tr);
         text.trans (db::Trans (text.trans ().rot (), scaled_and_snapped_vector (text.trans ().disp (), g, m, d, tr_disp.x (), g, m, d, tr_disp.y ())));
         text.transform (trinv);
-        out.insert (text);
+
+        if (si->has_prop_id ()) {
+          new_shapes.insert (db::TextWithProperties (text, si->prop_id ()));
+        } else {
+          new_shapes.insert (text);
+        }
 
       }
 
-      s.swap (out);
-      out.clear ();
+      for (db::Shapes::shape_iterator si = s.begin (db::ShapeIterator::Edges); ! si.at_end (); ++si) {
+
+        db::Edge edge;
+        si->edge (edge);
+        edge.transform (tr);
+        edge = scaled_and_snapped_edge (edge, g, m , d, tr_disp.x (), tr_disp.y ());
+        edge.transform (trinv);
+
+        if (si->has_prop_id ()) {
+          new_shapes.insert (db::EdgeWithProperties (edge, si->prop_id ()));
+        } else {
+          new_shapes.insert (edge);
+        }
+
+      }
+
+      for (db::Shapes::shape_iterator si = s.begin (db::ShapeIterator::EdgePairs); ! si.at_end (); ++si) {
+
+        db::EdgePair edge_pair;
+        si->edge_pair (edge_pair);
+        edge_pair.transform (tr);
+        edge_pair = db::EdgePair (scaled_and_snapped_edge (edge_pair.first (), g, m , d, tr_disp.x (), tr_disp.y ()),
+                                  scaled_and_snapped_edge (edge_pair.second (), g, m , d, tr_disp.x (), tr_disp.y ()));
+        edge_pair.transform (trinv);
+
+        if (si->has_prop_id ()) {
+          new_shapes.insert (db::EdgePairWithProperties (edge_pair, si->prop_id ()));
+        } else {
+          new_shapes.insert (edge_pair);
+        }
+
+      }
+
+      s.swap (new_shapes);
 
     }
 
     //  Snap instance placements to grid and magnify
     //  NOTE: we can modify the instances because the ScaleAndGridReducer marked every cell with children
     //  as a variant cell (an effect of ScaleAndGridReducer::want_variants(cell) == true where cells have children).
-    //  Variant cells are not copied blindly back to the original layout.
-
-    std::list<db::CellInstArray> new_insts;
+    //  The variant formation also made sure the iterated and regular arrays are exploded where required.
 
     for (db::Cell::const_iterator inst = c->begin (); ! inst.at_end (); ++inst) {
 
       const db::CellInstArray &ia = inst->cell_inst ();
-      for (db::CellInstArray::iterator i = ia.begin (); ! i.at_end (); ++i) {
 
-        db::Trans ti (*i);
-        db::Vector ti_disp = ti.disp ();
-        ti_disp.transform (tr);
-        ti_disp = scaled_and_snapped_vector (ti_disp, g, m, d, tr_disp.x (), g, m, d, tr_disp.y ());
-        ti_disp.transform (trinv);
-        ti.disp (ti_disp);
+      iterated_array_vectors.clear ();
+      db::Vector a, b;
+      unsigned long na, nb;
 
-        if (ia.is_complex ()) {
-          new_insts.push_back (db::CellInstArray (ia.object (), ia.complex_trans (ti)));
-        } else {
-          new_insts.push_back (db::CellInstArray (ia.object (), ti));
+      db::CellInstArray new_array (ia);
+
+      if (ia.is_iterated_array (&iterated_array_vectors)) {
+
+        bool needs_update = false;
+        for (std::vector<db::Vector>::iterator i = iterated_array_vectors.begin (); i != iterated_array_vectors.end (); ++i) {
+          db::Vector v = scaled_and_snapped_vector (*i, g, m, d, tr_disp.x (), g, m, d, tr_disp.y ());
+          if (v != *i) {
+            needs_update = true;
+            *i = v;
+          }
         }
 
+        if (needs_update) {
+          new_array = db::CellInstArray (ia.object (), ia.complex_trans (ia.front ()), iterated_array_vectors.begin (), iterated_array_vectors.end ());
+        }
+
+      } else if (ia.is_regular_array (a, b, na, nb)) {
+
+        a = scaled_and_snapped_vector (a, g, m, d, tr_disp.x (), g, m, d, tr_disp.y ());
+        b = scaled_and_snapped_vector (b, g, m, d, tr_disp.x (), g, m, d, tr_disp.y ());
+
+        new_array = db::CellInstArray (ia.object (), ia.complex_trans (ia.front ()), a, b, na, nb);
+
       }
 
-    }
+      scale_and_snap_cell_instance (new_array, tr, trinv, tr_disp, g, m, d);
+      c->replace (*inst, new_array);
 
-    c->clear_insts ();
-
-    for (std::list<db::CellInstArray>::const_iterator i = new_insts.begin (); i != new_insts.end (); ++i) {
-      c->insert (*i);
     }
 
   }
diff --git a/src/db/db/dbTestSupport.cc b/src/db/db/dbTestSupport.cc
index aa5522df0..090e849a2 100644
--- a/src/db/db/dbTestSupport.cc
+++ b/src/db/db/dbTestSupport.cc
@@ -138,7 +138,7 @@ void compare_layouts (tl::TestBase *_this, const db::Layout &layout, const std::
       equal = db::compare_layouts (*subject, layout_au,
                                      (n > 0 ? db::layout_diff::f_silent : db::layout_diff::f_verbose)
                                      | ((norm & AsPolygons) != 0 ? db::layout_diff::f_boxes_as_polygons + db::layout_diff::f_paths_as_polygons : 0)
-                                     | db::layout_diff::f_flatten_array_insts
+                                     | ((norm & WithArrays) != 0 ? 0 : db::layout_diff::f_flatten_array_insts)
                                    /*| db::layout_diff::f_no_text_details | db::layout_diff::f_no_text_orientation*/
                                    , tolerance, 100 /*max diff lines*/);
       if (equal && n > 0) {
diff --git a/src/db/db/dbTestSupport.h b/src/db/db/dbTestSupport.h
index 9b031fdce..8f89cf7e9 100644
--- a/src/db/db/dbTestSupport.h
+++ b/src/db/db/dbTestSupport.h
@@ -56,7 +56,8 @@ enum NormalizationMode
   WriteOAS = 2,           //  normalize subject by writing to OASIS and reading back
   NormFileMask = 7,       //  bits the extract for file mode
   NoContext = 8,          //  write tmp file without context
-  AsPolygons = 16         //  paths and boxes are treated as polygons
+  AsPolygons = 16,        //  paths and boxes are treated as polygons
+  WithArrays = 32         //  do not flatten arrays
 };
 
 /**
diff --git a/src/db/unit_tests/dbD25TechnologyComponentTests.cc b/src/db/unit_tests/dbD25TechnologyComponentTests.cc
deleted file mode 100644
index 30ac2b807..000000000
--- a/src/db/unit_tests/dbD25TechnologyComponentTests.cc
+++ /dev/null
@@ -1,102 +0,0 @@
-
-/*
-
-  KLayout Layout Viewer
-  Copyright (C) 2006-2022 Matthias Koefferlein
-
-  This program is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-
-*/
-
-
-
-#include "dbD25TechnologyComponent.h"
-#include "tlUnitTest.h"
-
-
-TEST(1)
-{
-  db::D25TechnologyComponent comp;
-
-  comp.set_src ("1/0: 1.0 1.5 # a comment");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5");
-
-  comp.set_src ("1/0: zstart=1.0 zstop=1.5");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5");
-
-  comp.set_src ("1/0: zstart=1.0 height=0.5");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5");
-
-  comp.set_src ("1/0: 1.0 height=0.5");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5");
-
-  comp.set_src ("1/0: zstop=1.5 height=0.5");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5");
-
-  comp.set_src ("1/0: zstart=1.0 zstop=1.5\nname: height=3");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5\nname: zstart=1.5, zstop=4.5");
-
-  comp.set_src ("1/0: zstart=1.0 zstop=1.5\nname: zstart=4.0 height=3\n\n# a comment line");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5\nname: zstart=4, zstop=7");
-
-  comp.set_src ("var x=1.0\n1/0: zstart=x zstop=x+0.5\nname: zstart=4.0 height=3\n\n# a comment line");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5\nname: zstart=4, zstop=7");
-
-  comp.set_src ("var x=1.0\nif x == 1.0\n1/0: zstart=x zstop=x+0.5\nelse\n1/0: zstart=0 zstop=0\nend\nname: zstart=4.0 height=3\n\n# a comment line");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=1, zstop=1.5\nname: zstart=4, zstop=7");
-
-  comp.set_src ("var x=2.0\nif x == 1.0\n1/0: zstart=x zstop=x+0.5\nelse\n1/0: zstart=0 zstop=0\nend\nname: zstart=4.0 height=3\n\n# a comment line");
-  comp.compile_from_source ();
-  EXPECT_EQ (comp.to_string (), "1/0: zstart=0, zstop=0\nname: zstart=4, zstop=7");
-
-  try {
-    comp.set_src ("blabla");
-    comp.compile_from_source ();
-    EXPECT_EQ (false, true);
-  } catch (...) { }
-
-  try {
-    comp.set_src ("1/0: 1 2 3");
-    comp.compile_from_source ();
-    EXPECT_EQ (false, true);
-  } catch (...) { }
-
-  try {
-    comp.set_src ("1/0: foo=1 bar=2");
-    comp.compile_from_source ();
-    EXPECT_EQ (false, true);
-  } catch (...) { }
-
-  try {
-    comp.set_src ("1/0: 1;*2");
-    comp.compile_from_source ();
-    EXPECT_EQ (false, true);
-  } catch (...) { }
-
-  try {
-    comp.set_src ("error 42");
-    comp.compile_from_source ();
-    EXPECT_EQ (false, true);
-  } catch (...) { }
-}
diff --git a/src/db/unit_tests/dbLayoutUtilsTests.cc b/src/db/unit_tests/dbLayoutUtilsTests.cc
index 3dac06878..26130e050 100644
--- a/src/db/unit_tests/dbLayoutUtilsTests.cc
+++ b/src/db/unit_tests/dbLayoutUtilsTests.cc
@@ -25,6 +25,8 @@
 #include "dbCellMapping.h"
 #include "dbTestSupport.h"
 #include "dbReader.h"
+#include "dbLayoutDiff.h"
+#include "dbPropertiesRepository.h"
 #include "tlString.h"
 #include "tlUnitTest.h"
 
@@ -653,3 +655,127 @@ TEST(18_scale_and_snap)
   CHECKPOINT();
   db::compare_layouts (_this, l1, tl::testdata () + "/algo/layout_utils_au_sns3.gds");
 }
+
+TEST(19_scale_and_snap_basic)
+{
+  db::Layout l1;
+  db::Layout l2;
+
+  db::PropertiesRepository::properties_set ps1;
+  ps1.insert (std::make_pair (l1.properties_repository ().prop_name_id (tl::Variant ("p")), tl::Variant (17)));
+  db::properties_id_type pid1 = l1.properties_repository ().properties_id (ps1);
+
+  db::PropertiesRepository::properties_set ps2;
+  ps2.insert (std::make_pair (l2.properties_repository ().prop_name_id (tl::Variant ("p")), tl::Variant (17)));
+  db::properties_id_type pid2 = l2.properties_repository ().properties_id (ps2);
+
+  db::Cell &top1 = l1.cell (l1.add_cell ("TOP"));
+  db::Cell &top2 = l2.cell (l2.add_cell ("TOP"));
+
+  db::Cell &a1 = l1.cell (l1.add_cell ("A"));
+  db::Cell &a2a = l2.cell (l2.add_cell ("A"));
+
+  unsigned int layer1 = l1.insert_layer (db::LayerProperties (1, 0));
+  unsigned int layer2 = l2.insert_layer (db::LayerProperties (1, 0));
+
+  a1.shapes (layer1).insert (db::Box (0, 0, 100, 100));
+  a2a.shapes (layer2).insert (db::Box (0, 0, 100, 100));
+
+  top1.shapes (layer1).insert (db::Box (11, 21, 31, 41));
+  top2.shapes (layer2).insert (db::Box (10, 20, 30, 40));
+
+  top1.shapes (layer1).insert (db::BoxWithProperties (db::Box (11, 21, 31, 41), pid1));
+  top2.shapes (layer2).insert (db::BoxWithProperties (db::Box (10, 20, 30, 40), pid2));
+
+  top1.shapes (layer1).insert (db::Edge (11, 21, 31, 41));
+  top2.shapes (layer2).insert (db::Edge (10, 20, 30, 40));
+
+  top1.shapes (layer1).insert (db::EdgeWithProperties (db::Edge (11, 21, 31, 41), pid1));
+  top2.shapes (layer2).insert (db::EdgeWithProperties (db::Edge (10, 20, 30, 40), pid2));
+
+  top1.shapes (layer1).insert (db::EdgePair (db::Edge (11, 21, 31, 41), db::Edge (111, 121, 131, 141)));
+  top2.shapes (layer2).insert (db::EdgePair (db::Edge (10, 20, 30, 40), db::Edge (110, 120, 130, 140)));
+
+  top1.shapes (layer1).insert (db::EdgePairWithProperties (db::EdgePair (db::Edge (11, 21, 31, 41), db::Edge (111, 121, 131, 141)), pid1));
+  top2.shapes (layer2).insert (db::EdgePairWithProperties (db::EdgePair (db::Edge (10, 20, 30, 40), db::Edge (110, 120, 130, 140)), pid2));
+
+  top1.shapes (layer1).insert (db::Polygon (db::Box (11, 21, 31, 41)));
+  top2.shapes (layer2).insert (db::Polygon (db::Box (10, 20, 30, 40)));
+
+  top1.shapes (layer1).insert (db::PolygonWithProperties (db::Polygon (db::Box (11, 21, 31, 41)), pid1));
+  top2.shapes (layer2).insert (db::PolygonWithProperties (db::Polygon (db::Box (10, 20, 30, 40)), pid2));
+
+  db::Point pts1[] = {
+    db::Point (1, 101),
+    db::Point (101, 101),
+    db::Point (101, 201)
+  };
+
+  db::Point pts2[] = {
+    db::Point (0, 100),
+    db::Point (100, 100),
+    db::Point (100, 200)
+  };
+
+  top1.shapes (layer1).insert (db::Path (&pts1 [0], &pts1 [sizeof (pts1) / sizeof(pts1 [0])], 20));
+  top2.shapes (layer2).insert (db::Path (&pts2 [0], &pts2 [sizeof (pts2) / sizeof(pts2 [0])], 20));
+
+  top1.shapes (layer1).insert (db::PathWithProperties (db::Path (&pts1 [0], &pts1 [sizeof (pts1) / sizeof(pts1 [0])], 20), pid1));
+  top2.shapes (layer2).insert (db::PathWithProperties (db::Path (&pts2 [0], &pts2 [sizeof (pts2) / sizeof(pts2 [0])], 20), pid2));
+
+  top1.shapes (layer1).insert (db::Text ("t1", db::Trans (db::Vector (11, 21))));
+  top2.shapes (layer2).insert (db::Text ("t1", db::Trans (db::Vector (10, 20))));
+
+  top1.shapes (layer1).insert (db::TextWithProperties (db::Text ("t1", db::Trans (db::Vector (11, 21))), pid1));
+  top2.shapes (layer2).insert (db::TextWithProperties (db::Text ("t1", db::Trans (db::Vector (10, 20))), pid2));
+
+  top1.insert (db::CellInstArray (db::CellInst (a1.cell_index ()), db::Trans (db::Vector (11, 21))));
+  top2.insert (db::CellInstArray (db::CellInst (a2a.cell_index ()), db::Trans (db::Vector (10, 20))));
+
+  top1.insert (db::CellInstArrayWithProperties (db::CellInstArray (db::CellInst (a1.cell_index ()), db::Trans (db::Vector (11, 21))), pid1));
+  top2.insert (db::CellInstArrayWithProperties (db::CellInstArray (db::CellInst (a2a.cell_index ()), db::Trans (db::Vector (10, 20))), pid2));
+
+  top1.insert (db::CellInstArray (db::CellInst (a1.cell_index ()), db::Trans (db::Vector (11, 21)), db::Vector (0, 10), db::Vector (10, 0), 2, 3));
+  top2.insert (db::CellInstArray (db::CellInst (a2a.cell_index ()), db::Trans (db::Vector (10, 20)), db::Vector (0, 10), db::Vector (10, 0), 2, 3));
+
+  top1.insert (db::CellInstArrayWithProperties (db::CellInstArray (db::CellInst (a1.cell_index ()), db::Trans (db::Vector (11, 21)), db::Vector (0, 10), db::Vector (10, 0), 2, 3), pid1));
+  top2.insert (db::CellInstArrayWithProperties (db::CellInstArray (db::CellInst (a2a.cell_index ()), db::Trans (db::Vector (10, 20)), db::Vector (0, 10), db::Vector (10, 0), 2, 3), pid2));
+
+  std::vector<db::Vector> ia;
+  ia.push_back (db::Vector (0, 0));
+  ia.push_back (db::Vector (10, 0));
+  ia.push_back (db::Vector (0, 10));
+
+  top1.insert (db::CellInstArray (db::CellInst (a1.cell_index ()), db::Trans (db::Vector (11, 21)), ia.begin (), ia.end ()));
+  top2.insert (db::CellInstArray (db::CellInst (a2a.cell_index ()), db::Trans (db::Vector (10, 20)), ia.begin (), ia.end ()));
+
+  top1.insert (db::CellInstArrayWithProperties (db::CellInstArray (db::CellInst (a1.cell_index ()), db::Trans (db::Vector (11, 21)), ia.begin (), ia.end ()), pid1));
+  top2.insert (db::CellInstArrayWithProperties (db::CellInstArray (db::CellInst (a2a.cell_index ()), db::Trans (db::Vector (10, 20)), ia.begin (), ia.end ()), pid2));
+
+  db::scale_and_snap (l1, top1, 10, 1, 1);
+
+  bool equal = db::compare_layouts (l1, l2,
+                                     db::layout_diff::f_verbose
+                                     | db::layout_diff::f_boxes_as_polygons
+                                     | db::layout_diff::f_paths_as_polygons
+                                   , 0, 100 /*max diff lines*/);
+  EXPECT_EQ (equal, true);
+}
+
+TEST(20_scale_and_snap)
+{
+  db::Layout l1;
+  {
+    std::string fn (tl::testdata ());
+    fn += "/algo/scale_and_snap4.oas";
+    tl::InputStream stream (fn);
+    db::Reader reader (stream);
+    reader.read (l1);
+  }
+
+  db::scale_and_snap (l1, l1.cell (*l1.begin_top_down ()), 10, 95, 100);
+
+  CHECKPOINT();
+  db::compare_layouts (_this, l1, tl::testdata () + "/algo/layout_utils_au_sns4.oas", db::NormalizationMode (db::WriteOAS + db::WithArrays));
+}
+
diff --git a/src/db/unit_tests/unit_tests.pro b/src/db/unit_tests/unit_tests.pro
index 8601dfb65..ffe564cb9 100644
--- a/src/db/unit_tests/unit_tests.pro
+++ b/src/db/unit_tests/unit_tests.pro
@@ -39,7 +39,6 @@ SOURCES = \
     dbPolygonToolsTests.cc \
     dbTechnologyTests.cc \
     dbStreamLayerTests.cc \
-    dbD25TechnologyComponentTests.cc \
     dbVectorTests.cc \
     dbVariableWidthPathTests.cc \
     dbTransTests.cc \
diff --git a/src/drc/drc/built-in-macros/_drc_engine.rb b/src/drc/drc/built-in-macros/_drc_engine.rb
index 3600355ca..9bf0556a0 100644
--- a/src/drc/drc/built-in-macros/_drc_engine.rb
+++ b/src/drc/drc/built-in-macros/_drc_engine.rb
@@ -1626,6 +1626,54 @@ CODE
       nil
     end
 
+    # %DRC%
+    # @name region_touch 
+    # @brief Specifies region selected input in "touch mode"
+    # @synopsis region_touch(args)
+    # See \Source#touching for a description of that function.
+    #
+    # The following code will select shapes touching a 500x600 micron rectangle (lower left corner at 0,0) 
+    # from the input layout. The shapes will not be clipped:
+    # 
+    # @code
+    # region_touch(0.mm, 0.mm, 0.5.mm, 0.6.mm)
+    # # shapes will now be the ones touching the rectangular region
+    # l1 = input(1, 0)
+    # @/code
+    # 
+    # To remove this condition, call "region_touch" without any arguments.
+ 
+    def region_touch(*args)
+      self._context("region_touch") do
+        @def_source = layout.touching(*args)
+      end
+      nil
+    end
+
+    # %DRC%
+    # @name region_overlap 
+    # @brief Specifies region selected input in "overlap mode"
+    # @synopsis region_overlap(args)
+    # See \Source#overlapping for a description of that function.
+    #
+    # The following code will select shapes overlapping a 500x600 micron rectangle (lower left corner at 0,0) 
+    # from the input layout. The shapes will not be clipped:
+    # 
+    # @code
+    # region_overlapping(0.mm, 0.mm, 0.5.mm, 0.6.mm)
+    # # shapes will now be the ones overlapping the rectangular region
+    # l1 = input(1, 0)
+    # @/code
+    # 
+    # To remove this condition, call "region_overlapping" without any arguments.
+ 
+    def region_overlap(*args)
+      self._context("region_overlap") do
+        @def_source = layout.overlapping(*args)
+      end
+      nil
+    end
+
     # %DRC%
     # @name global_transform
     # @brief Gets or sets a global transformation
diff --git a/src/drc/drc/built-in-macros/drc_interpreters.lym b/src/drc/drc/built-in-macros/drc_interpreters.lym
index 4a0108d44..a5c4d13ed 100644
--- a/src/drc/drc/built-in-macros/drc_interpreters.lym
+++ b/src/drc/drc/built-in-macros/drc_interpreters.lym
@@ -158,6 +158,11 @@ module DRC
   # Register the new interpreters
   DRCInterpreter::new(drc_recipe)
   DRCPlainTextInterpreter::new(drc_recipe)
+
+  # Creates a new macro category
+  if RBA::Application::instance 
+    RBA::Application::instance.add_macro_category("drc", "DRC", [ "drc" ])
+  end
  
 end
 </text>
diff --git a/src/gtfui/gtfUiDialog.cc b/src/gtfui/gtfUiDialog.cc
index 395dc2eec..504760616 100644
--- a/src/gtfui/gtfUiDialog.cc
+++ b/src/gtfui/gtfUiDialog.cc
@@ -264,7 +264,7 @@ static std::string
 log_event_to_text (const gtf::LogEventBase *e)
 {
   std::string t = e->name ();
-  /* @@@ too much:
+  /* too much:
   std::vector< std::pair<std::string, std::string> > attrs;
   e->attributes (attrs);
   for (std::vector< std::pair<std::string, std::string> >::const_iterator a = attrs.begin (); a != attrs.end (); ++a) {
diff --git a/src/lay/lay/MacroPropertiesDialog.ui b/src/lay/lay/MacroPropertiesDialog.ui
index d7a2c29e8..1a281dac4 100644
--- a/src/lay/lay/MacroPropertiesDialog.ui
+++ b/src/lay/lay/MacroPropertiesDialog.ui
@@ -100,7 +100,6 @@
           <widget class="QLabel" name="interpreterLabel">
            <property name="font">
             <font>
-             <weight>75</weight>
              <bold>true</bold>
             </font>
            </property>
@@ -224,25 +223,56 @@
              <number>6</number>
             </property>
             <item row="0" column="0">
+             <widget class="QLabel" name="label_11">
+              <property name="text">
+               <string>Priority</string>
+              </property>
+             </widget>
+            </item>
+            <item row="1" column="0">
              <widget class="QLabel" name="label_10">
               <property name="text">
                <string>Prolog</string>
               </property>
              </widget>
             </item>
-            <item row="0" column="1">
-             <widget class="QLineEdit" name="prolog"/>
-            </item>
-            <item row="1" column="1">
-             <widget class="QLineEdit" name="epilog"/>
-            </item>
-            <item row="1" column="0">
+            <item row="2" column="0">
              <widget class="QLabel" name="label_7">
               <property name="text">
                <string>Epilog</string>
               </property>
              </widget>
             </item>
+            <item row="0" column="1">
+             <widget class="QLineEdit" name="priority">
+              <property name="sizePolicy">
+               <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+                <horstretch>0</horstretch>
+                <verstretch>0</verstretch>
+               </sizepolicy>
+              </property>
+             </widget>
+            </item>
+            <item row="0" column="2">
+             <widget class="QLabel" name="label_12">
+              <property name="text">
+               <string>for autorun: 0 = first, 1 = second ...</string>
+              </property>
+             </widget>
+            </item>
+            <item row="1" column="1" colspan="2">
+             <widget class="QLineEdit" name="prolog">
+              <property name="sizePolicy">
+               <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+                <horstretch>1</horstretch>
+                <verstretch>0</verstretch>
+               </sizepolicy>
+              </property>
+             </widget>
+            </item>
+            <item row="2" column="1" colspan="2">
+             <widget class="QLineEdit" name="epilog"/>
+            </item>
            </layout>
           </widget>
          </item>
diff --git a/src/lay/lay/doc/about/25d_screenshot.png b/src/lay/lay/doc/about/25d_screenshot.png
index 1796a0573..32c96174e 100644
Binary files a/src/lay/lay/doc/about/25d_screenshot.png and b/src/lay/lay/doc/about/25d_screenshot.png differ
diff --git a/src/lay/lay/doc/about/25d_screenshot2.png b/src/lay/lay/doc/about/25d_screenshot2.png
new file mode 100644
index 000000000..5c988166f
Binary files /dev/null and b/src/lay/lay/doc/about/25d_screenshot2.png differ
diff --git a/src/lay/lay/doc/about/25d_view.xml b/src/lay/lay/doc/about/25d_view.xml
index a23667f30..22438889e 100644
--- a/src/lay/lay/doc/about/25d_view.xml
+++ b/src/lay/lay/doc/about/25d_view.xml
@@ -18,97 +18,187 @@
   </p>
 
   <p>
-  To open the view, use "Tools/2.5d View". Currently, the performance is limited, a rough number for a
+  Currently, the performance is limited, a rough number for a
   practical limit is around 100k polygons. The 2.5d view is only available, if KLayout was compiled with
   OpenGL support.
   </p>
 
+  <p>
+  In order to use the tool, you will need a script generating the material stack.
+  Such a script is a variant of a DRC script (see <link href="/manual/drc.xml"/>). 
+  The DRC language is used to import or generate polygon layers which are then
+  extruded and placed on a certain z level.
+  </p>
+
+  <p>
+  To create a new script, use "Tools/2.5d View/New 2.5d Script". This will create a new script in the
+  macro editor. 
+  </p>
+
+  <p>
+  A simple script is this one. It takes two layers - 1/0 and 2/0 - and extrudes then in a 
+  stacked fashion, the first with 200nm thickness and the second one with 300nm:
+  </p>
+
+  <pre>
+z(input(1, 0), zstart: 0.1.um, height: 200.nm)  # extrudes layer 1/0 to a height of 200nm starting at z=100nm
+z(input(2, 0), height: 300.nm)                  # adds layer 2/0 for the next 300nm
+</pre>
+
+  <p>
+  To run the script, use the "Run" button from the macro IDE or pick the script
+  from the script list in the "Tools/2.5d View" menu. If your script is not shown in that 
+  menu, check if it is configured to be bound to a menu item.
+  </p>
+
+  <p>
+  After the script was executed, the 2.5d window is displayed. If you closed that window, you can 
+  re-open it with "Tools/2.5d View/Open Window". The window will show the layout section visible 
+  in the layout view. To refresh the scene - also after changing the script - either run the script
+  again from the macro IDE or use the green "re-run" button in the upper left corner of the 2.5d view
+  window.
+  </p>
+
   <p>
   <img src="/about/25d_screenshot.png"/>
   </p>
 
-  <h2>Setup</h2>
+  <h2>2.5d Script Anatomy</h2>
 
   <p>
-  The 2.5d view needs a technology setup explaining the way the layers are transformed into planes.
-  The setup is provided within a technology. Open the technology manager (File/Manage Technologies) and
-  navigate to the "Z Stack (2.5d)" component. The setup is basically a list of entries listing the 
-  layer from which to take the shapes and the depth information.
-  </p>
-
-  <p>
-  Each entry is a single line. Empty lines are ignored. Everything after a '#' character is 
-  considered a comment.
-  </p>
-
-  <p>
-  Each specification line consists of a layer specification, a colon and arguments.
-  The arguments are named (like "x=...") or in serial. Parameters are separated by comma or blanks.
-  Named arguments are:
+  As mentioned, a 2.5d script is a variant of a DRC script. You can basically use all features
+  of DRC, specifically boolean operations. Some practical restrictions exist:
   </p>
 
   <ul>
-    <li> <b>zstart</b>:  The lower z position of the extruded layer in µm </li>
-    <li> <b>zstop</b>: The upper z position of the extruded layer in µm </li>
-    <li> <b>height</b>:  The height of the extruded layer in µm </li>
+    <li>You should not use external sources ("source" statement) as the 2.5d view is related to the loaded layout</li>
+    <li>Report generation or "output" statements are permitted, but do not make much sense in the context
+        of 2.5d view scripts.</li>
   </ul>
 
   <p>
-  'height', 'zstart' and 'zstop' can be used in any combination. If no value is given for 'zstart',
-  the upper level of the previous layer will be used.
+  2.5d scripts utilizes the DRC language with these two additional functions:
+  </p>
+
+  <ul>
+    <li><p><tt>z(</tt>layer [, options]<tt>)</tt></p>
+        <p>Extrudes the given layer. "layer" is a DRC layer (polygon, edge or even edge pair). "options" declare the z extrusion and display parameters.</p>
+    </li>
+    <li><p><tt>zz(</tt> [options] <tt>) {</tt> block <tt>}</tt></p>
+        <p>Declares a material group which combines multiple "z" statements under a single display group.
+           This allows generating 3d material geometries which are more than a single extruded plane.
+           The display parameters then are specified within "zz" for all "z" calls inside the block.</p>
+    </li>
+  </ul>
+
+  <h3>"z" Function (plane extrusion)</h3>
+  <keyword name="z"/>
+
+  <p>
+  The layer argument of the function is a DRC layer which is rendered as an extruded sheet.
+  Further arguments control the height, z location and colors.
+  When used inside the "zz" block, the color options of the "z" calls are ignored and 
+  taken from "zz" instead.
   </p>
 
   <p>
-  If a single unnamed parameter is given, it corresponds to 'height'. Two parameters correspond to
-  'zstart' and 'zstop'.
+  Options for this function are:
   </p>
 
+  <ul>
+    <li><b>zstart</b>: specifies the bottom coordinate of the extruded sheet. If this option is not given, the top coordinate of the previous "z" statement is used.</li>
+    <li><b>zstop</b>: specifies the top coordinate of the extruded sheet. Alternatively you can use "height".</li>
+    <li><b>height</b>: specifies the extrusion height. Alternatively you can use "zstop".</li>
+    <li><b>color</b>: specifies the color to use as a 24 bit hex RGB triplet (use "0xrrggbb" to specify the color similar to the HTML notation "#rrggbb").
+                        A color specification gives a single color with not differentiation of frame and wall colors.</li>
+    <li><b>frame</b>: specifies the frame color to use as a 24 bit hex RGB triplet. If only a frame color is specified, the geometry will be rendered as wire frame only.</li>
+    <li><b>fill</b>: specifies the fill (wall) color to use as a 24 bit hex RGB triplet. This allows specifying a different color for wall and frame when used with "frame".</li>
+    <li><b>like</b>: specifies to use the same colors than used for some layer in the layout view. 
+                        If the layer is an original layer (i.e. taken from "input"), "like" defaults to the 
+                        original layer's source. If given, "like" needs to be a string representation of the
+                        layer source (e.g. "7/0" for layer 7, datatype 0).</li>
+    <li><b>name</b>: gives the material a name for displaying in the material list.</li>
+  </ul>
+
   <p>
-  Here are some examples:
+  Examples for the extrusion options:
   </p>
 
-  <pre>1: 0.5 1.5                    # extrude layer 1/0 from 0.5 to 1.5 vertically\n"
-1/0: 0.5 1.5                  # same with explicit datatype\n"
-1: zstop=1.5, zstart=0.5      # same with named parameters\n"
-1: height=1.0, zstop=1.5      # same with z stop minus height\n"
-1: 1.0 zstop=1.5              # same with height as unnamed parameter\n"
-  </pre>
-
-  <h4>Variables</h4>
-
-  <p>
-  You can declare variables inside the setup files and use them in formulas for
-  computed values. Variables are defined and set with the "var" keyword on a single line.
-  The notation follows the "expression" syntax used in many other places inside KLayout
-  (<link href="/about/expressions.xml"/>).
-  </p>
-
-  <p>
-  Here is an example:
-  </p>
-
-  <pre>var hmetal = 0.48\n"
-7/0: 0.5 0.5+hmetal*2        # 2x thick metal\n"
+  <pre>
+z(layer, 0.1 .. 0.2)                extrude layer to z = 0.1 to 0.2 um
+z(layer, zstart: 0.1, zstop: 0.2)   same as above
+z(layer, zstart: 0.1, height: 0.1)  same as above, but with height instead of zstop
+z(layer, height: 200.nm)            extrude layer from last z position with a height of 200nm
 </pre>
 
-  <h4>Conditionals</h4>
-
   <p>
-  For more flexibility, but of little practical use for now, conditionals are provided.
-  "if", "else", "elsif" and "end" for as in other languages, e.g. Ruby:
+  Examples for display options:
   </p>
 
-  <pre>var thick_m1 = true
-if thickm1
-  1: 0.5 1.5
-else
-  1: 0.5 1.2
+  <pre>
+z(..., color: 0xff0000)             use bright red for the material color (RGB)
+z(..., frame: 0xff0000)             use bright red for the frame color (combine with "fill" for the fill color)
+z(..., fill: 0x00ff00)              use bright green for the fill color along (combine with "frame" for the frame color)
+z(..., like: "7/0")                 borrow style from layout view's style for layer "7/0"
+z(..., name: "M1")                  assigns a name to show for the material 
+</pre>
+
+  <h3>"zz" Function (material groups)</h3>
+  <keyword name="zz"/>
+
+  <p>
+  The "zz" function forms a display group which clusters multiple "z" calls. The basic usage is with a block
+  containing the "z" calls. As DRC scripts are Ruby, the notation for the block is either "do .. end" or 
+  curly brackets immediately after the "zz" call:
+  </p>
+
+  <pre>
+zz( display options ... ) do
+  z(layer1, extrusion options ... )
+  z(layer2, extrusion options ... )
+  ...
 end
 </pre>
 
+  <p>
+  The "z" calls do not need to have colors or other display options as they are
+  taken from "zz".
+  </p>
+
+  <p>
+  Material groups allow forming more complex, stacked geometries. Here is an example
+  forming a simple FinFET geometry using boolean and a sizing operation:
+  </p>
+
+  <pre>
+poly = input(2, 0)
+active = input(1, 0)
+
+z(poly, zstart: 0, height: 20.nm, name: "POLY")
+
+zz(name: "ACTIVE", like: "1/0") do
+  
+  poly_sized = poly.sized(10.nm)
+  active_over_poly_sized = poly_sized &amp; active
+  
+  z(active - poly, zstart: 0, height: 10.nm)       # bottom sheet
+  z(active_over_poly_sized - poly, height: 10.nm)  # center sheet
+  z(active_over_poly_sized, height: 10.nm)         # top sheet
+
+end
+</pre>
+
+  <p>
+  Which renders this result:
+  </p>
+
+  <p>
+  <img src="/about/25d_screenshot2.png"/>
+  </p>
+
   <h2>Navigating the 2.5d View</h2>
-  <keyword>navigation</keyword>
-  <keyword>2.5d navigation</keyword>
+  <keyword name="navigation"/>
+  <keyword name="2.5d view navigation"/>
 
   <p>
   The navigation is based on the movement of the camera while the scene is 
@@ -159,7 +249,7 @@ end
   made invisible in the 2.5d view.
   </p>
 
-  <h2>Other controls</h2>
+  <h2>Other Controls</h2>
 
   <p>
   The left zoom slider changes the overall scale factor. The right slider only changes the z (height) axis zoom factor.
@@ -176,5 +266,13 @@ end
   front view, top view etc.
   </p>
 
+  <h2>Material Visibility</h2>
+
+  <p>
+  Using the check boxes from the material view right of the scene view you can disable
+  materials, so they are no longer rendered. From the material list's context menu, 
+  you can hide or show all materials or just the selected ones.
+  </p>
+
 </doc>
 
diff --git a/src/lay/lay/gsiDeclLayApplication.cc b/src/lay/lay/gsiDeclLayApplication.cc
index 287b80f92..fbf23517b 100644
--- a/src/lay/lay/gsiDeclLayApplication.cc
+++ b/src/lay/lay/gsiDeclLayApplication.cc
@@ -87,6 +87,12 @@ static std::string version (C *)
   return C::version ();
 }
 
+template <class C>
+static void add_macro_category (C *c, const std::string &name, const std::string &description, const std::vector<std::string> &folders)
+{
+  c->add_macro_category (name, description, folders);
+}
+
 template <class C>
 static gsi::Methods application_methods ()
 {
@@ -226,6 +232,12 @@ static gsi::Methods application_methods ()
       "@brief Returns the architecture string\n"
       "This method has been introduced in version 0.25."
     ) +
+    method_ext<C, const std::string &, const std::string &, const std::vector<std::string> &> ("add_macro_category", &add_macro_category<C>, gsi::arg ("name"), gsi::arg ("description"), gsi::arg ("folders"),
+      "@brief Creates a new macro category\n"
+      "Creating a new macro category is only possible during the autorun_early stage. "
+      "The new macro category must correspond to an interpreter registered at the same stage.\n"
+      "This method has been introduced in version 0.28."
+    ) +
     method<C *> ("instance", &C::instance,
       "@brief Return the singleton instance of the application\n"
       "\n"
diff --git a/src/lay/lay/layApplication.cc b/src/lay/lay/layApplication.cc
index f5d4dd505..a66c633a2 100644
--- a/src/lay/lay/layApplication.cc
+++ b/src/lay/lay/layApplication.cc
@@ -686,6 +686,22 @@ ApplicationBase::init_app ()
 
   if (mc) {
 
+    //  create the basic macro categories
+
+    if (ruby_interpreter ().available ()) {
+      std::vector<std::string> folders;
+      folders.push_back ("macros");
+      folders.push_back ("ruby");
+      mc->add_macro_category ("macros", "Ruby", folders);
+    }
+
+    if (python_interpreter ().available ()) {
+      std::vector<std::string> folders;
+      folders.push_back ("pymacros");
+      folders.push_back ("python");
+      mc->add_macro_category ("pymacros", "Python", folders);
+    }
+
     mc->enable_implicit_macros (! m_no_macros);
 
     //  Add the global ruby modules as the first ones.
@@ -741,13 +757,29 @@ ApplicationBase::init_app ()
     }
   }
 
+  std::set<std::string> already_executed;
+
   //  run all early autorun macros
-  lym::MacroCollection::root ().autorun_early ();
+  lym::MacroCollection::root ().autorun_early (&already_executed);
+
+  //  autorun_early may have added macro categories, so we need to call finish() again
+  if (mc) {
+
+    mc->finish ();
+
+    //  as this regenerates the macro collection, autorun_early is required again
+    //  note: this does no re-execute macros that have been executed already
+    lym::MacroCollection::root ().autorun_early (&already_executed);
+
+  }
 
   //  rescan the folders because early autorun macros might have added 
   //  suffixes through the MacroInterpreter interface.
   lym::MacroCollection::root ().rescan ();
 
+  //  and yet another autorun_early pass ..
+  lym::MacroCollection::root ().autorun_early (&already_executed);
+
   //  creates the main window or plugin root as required
   setup ();
 
@@ -785,6 +817,15 @@ ApplicationBase::init_app ()
   }
 }
 
+void
+ApplicationBase::add_macro_category (const std::string &name, const std::string &description, const std::vector<std::string> &folders)
+{
+  lay::MacroController *mc = lay::MacroController::instance ();
+  if (mc) {
+    mc->add_macro_category (name, description, folders);
+  }
+}
+
 ApplicationBase::~ApplicationBase ()
 {
   tl::set_ui_exception_handlers (0, 0, 0);
diff --git a/src/lay/lay/layApplication.h b/src/lay/lay/layApplication.h
index 85eb65267..887fc42c5 100644
--- a/src/lay/lay/layApplication.h
+++ b/src/lay/lay/layApplication.h
@@ -214,6 +214,13 @@ public:
     return *mp_python_interpreter;
   }
 
+  /**
+   *  @brief Adds a new macro category
+   *
+   *  This method is only effective when called during the autorun_early stage
+   */
+  void add_macro_category (const std::string &name, const std::string &description, const std::vector<std::string> &folders);
+
   /**
    *  @brief Return true, if undo buffering is enabled
    */
diff --git a/src/lay/lay/layHelpResources.qrc b/src/lay/lay/layHelpResources.qrc
index 06524e1f5..a853c8b3d 100644
--- a/src/lay/lay/layHelpResources.qrc
+++ b/src/lay/lay/layHelpResources.qrc
@@ -49,6 +49,7 @@
         <file alias="packages.xml">doc/about/packages.xml</file>
         <file alias="25d_view.xml">doc/about/25d_view.xml</file>
         <file alias="25d_screenshot.png">doc/about/25d_screenshot.png</file>
+        <file alias="25d_screenshot2.png">doc/about/25d_screenshot2.png</file>
     </qresource>
     <qresource prefix="/help/manual">
         <file alias="adjust_origin.xml">doc/manual/adjust_origin.xml</file>
diff --git a/src/lay/lay/layMacroController.cc b/src/lay/lay/layMacroController.cc
index 77bd03e20..51b1111ef 100644
--- a/src/lay/lay/layMacroController.cc
+++ b/src/lay/lay/layMacroController.cc
@@ -49,62 +49,27 @@ MacroController::MacroController ()
   //  .. nothing yet ..
 }
 
-static lay::MacroController::MacroCategory ruby_cat ()
+void
+MacroController::add_macro_category (const std::string &name, const std::string &description, const std::vector<std::string> &folders)
 {
   lay::MacroController::MacroCategory cat;
-  cat.name = "macros";
-  cat.description = tl::to_string (QObject::tr ("Ruby"));
-  cat.folders.push_back ("macros");
-  cat.folders.push_back ("ruby");
-  return cat;
-}
-
-static lay::MacroController::MacroCategory python_cat ()
-{
-  lay::MacroController::MacroCategory cat;
-  cat.name = "pymacros";
-  cat.description = tl::to_string (QObject::tr ("Python"));
-  cat.folders.push_back ("pymacros");
-  cat.folders.push_back ("python");
-  return cat;
-}
-
-static lay::MacroController::MacroCategory drc_cat ()
-{
-  lay::MacroController::MacroCategory cat;
-  cat.name = "drc";
-  cat.description = tl::to_string (QObject::tr ("DRC"));
-  cat.folders.push_back ("drc");
-  return cat;
-}
-
-static lay::MacroController::MacroCategory lvs_cat ()
-{
-  lay::MacroController::MacroCategory cat;
-  cat.name = "lvs";
-  cat.description = tl::to_string (QObject::tr ("LVS"));
-  cat.folders.push_back ("lvs");
-  return cat;
+  cat.name = name;
+  cat.description = description;
+  cat.folders = folders;
+  m_macro_categories.push_back (cat);
 }
 
 void
 MacroController::finish ()
 {
+  lym::MacroCollection::root ().clear ();
+
   //  Scan built-in macros
   //  These macros are always taken, even if there are no macros requested (they are required to
   //  fully form the API).
   lym::MacroCollection::root ().add_folder (tl::to_string (QObject::tr ("Built-In")), ":/built-in-macros", "macros", true);
   lym::MacroCollection::root ().add_folder (tl::to_string (QObject::tr ("Built-In")), ":/built-in-pymacros", "pymacros", true);
 
-  //  TODO: consider adding "drc" and "lvs" dynamically and allow more dynamic categories
-  //  We can do so if we first load the macros with the initial interpreters, then do autorun (which creates DSL interpreters) and then
-  //  register the remaining categories.
-
-  m_macro_categories.push_back (ruby_cat ());
-  m_macro_categories.push_back (python_cat ());
-  m_macro_categories.push_back (drc_cat ());
-  m_macro_categories.push_back (lvs_cat ());
-
   //  scans the macros from techs and packages (this will allow autorun-early on them)
   //  and updates m_external_paths
   sync_macro_sources ();
diff --git a/src/lay/lay/layMacroController.h b/src/lay/lay/layMacroController.h
index 757d92653..cae8e979b 100644
--- a/src/lay/lay/layMacroController.h
+++ b/src/lay/lay/layMacroController.h
@@ -147,10 +147,16 @@ public:
 
   /**
    *  @brief Loads the macros from the predefined paths and establishes the search paths
-   *  This method will also establish the macro categories.
+   *  This method can be called multiple times.
    */
   void finish ();
 
+  /**
+   *  @brief Adds a new macro category
+   *  finish() needs to be called after adding a new category.
+   */
+  void add_macro_category (const std::string &name, const std::string &description, const std::vector<std::string> &folders);
+
   /**
    *  @brief Adds a temporary macro
    *
diff --git a/src/lay/lay/layMacroPropertiesDialog.cc b/src/lay/lay/layMacroPropertiesDialog.cc
index 58fcf16f5..2c04a77c8 100644
--- a/src/lay/lay/layMacroPropertiesDialog.cc
+++ b/src/lay/lay/layMacroPropertiesDialog.cc
@@ -75,6 +75,7 @@ MacroPropertiesDialog::update (const lym::Macro *macro)
   propertiesFrame->setEnabled (! macro->is_readonly ());
   description->setText (tl::to_qstring (macro->description ()));
   version->setText (tl::to_qstring (macro->version ()));
+  priority->setText (tl::to_qstring (tl::to_string (macro->priority ())));
   prolog->setText (tl::to_qstring (macro->prolog ()));
   epilog->setText (tl::to_qstring (macro->epilog ()));
   autorun->setChecked (macro->is_autorun ());
@@ -98,6 +99,10 @@ MacroPropertiesDialog::commit (lym::Macro *macro)
   macro->set_show_in_menu (showmenu->isChecked ());
   macro->set_group_name (tl::to_string (groupName->text ()));
   macro->set_menu_path (tl::to_string (menuPath->text ()));
+
+  int p = 0;
+  tl::from_string (tl::to_string (priority->text ()), p);
+  macro->set_priority (p);
 }
 
 }
diff --git a/src/laybasic/laybasic/D25TechnologyComponentEditor.ui b/src/laybasic/laybasic/D25TechnologyComponentEditor.ui
deleted file mode 100644
index 19c8bfc39..000000000
--- a/src/laybasic/laybasic/D25TechnologyComponentEditor.ui
+++ /dev/null
@@ -1,55 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<ui version="4.0">
- <class>D25TechnologyComponentEditor</class>
- <widget class="QFrame" name="D25TechnologyComponentEditor">
-  <property name="geometry">
-   <rect>
-    <x>0</x>
-    <y>0</y>
-    <width>549</width>
-    <height>434</height>
-   </rect>
-  </property>
-  <property name="windowTitle">
-   <string>Settings</string>
-  </property>
-  <layout class="QGridLayout" name="gridLayout">
-   <item row="0" column="0">
-    <widget class="QLabel" name="label">
-     <property name="text">
-      <string>&lt;html&gt;2.5d Vertical stack information (see &lt;a href=&quot;int:/about/25d_view.xml&quot;&gt;here&lt;/a&gt; for details)&lt;/html&gt;</string>
-     </property>
-    </widget>
-   </item>
-   <item row="0" column="1">
-    <widget class="QLabel" name="lnum_label">
-     <property name="sizePolicy">
-      <sizepolicy hsizetype="Fixed" vsizetype="Preferred">
-       <horstretch>0</horstretch>
-       <verstretch>0</verstretch>
-      </sizepolicy>
-     </property>
-     <property name="text">
-      <string>Line</string>
-     </property>
-     <property name="alignment">
-      <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-     </property>
-    </widget>
-   </item>
-   <item row="1" column="0" colspan="2">
-    <widget class="QTextEdit" name="src_te">
-     <property name="lineWrapMode">
-      <enum>QTextEdit::NoWrap</enum>
-     </property>
-     <property name="acceptRichText">
-      <bool>false</bool>
-     </property>
-    </widget>
-   </item>
-  </layout>
- </widget>
- <layoutdefault spacing="6" margin="11"/>
- <resources/>
- <connections/>
-</ui>
diff --git a/src/laybasic/laybasic/layD25TechnologyComponent.cc b/src/laybasic/laybasic/layD25TechnologyComponent.cc
deleted file mode 100644
index af6bbee16..000000000
--- a/src/laybasic/laybasic/layD25TechnologyComponent.cc
+++ /dev/null
@@ -1,115 +0,0 @@
-
-/*
-
-  KLayout Layout Viewer
-  Copyright (C) 2006-2022 Matthias Koefferlein
-
-  This program is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-
-*/
-
-
-#include "laybasicConfig.h"
-#include "dbD25TechnologyComponent.h"
-#include "layD25TechnologyComponent.h"
-#include "layQtTools.h"
-
-#include <QResource>
-#include <QBuffer>
-
-namespace lay
-{
-
-D25TechnologyComponentEditor::D25TechnologyComponentEditor (QWidget *parent)
-  : TechnologyComponentEditor (parent)
-{
-  setupUi (this);
-
-  src_te->setFont (monospace_font ());
-
-  activate_help_links (label);
-
-  QResource res (tl::to_qstring (":/syntax/d25_text.xml"));
-  QByteArray data ((const char *) res.data (), int (res.size ()));
-#if QT_VERSION >= 0x60000
-  if (res.compressionAlgorithm () == QResource::ZlibCompression) {
-#else
-  if (res.isCompressed ()) {
-#endif
-    data = qUncompress (data);
-  }
-
-  QBuffer input (&data);
-  input.open (QIODevice::ReadOnly);
-  mp_hl_basic_attributes.reset (new GenericSyntaxHighlighterAttributes ());
-  mp_hl_attributes.reset (new GenericSyntaxHighlighterAttributes (mp_hl_basic_attributes.get ()));
-  lay::GenericSyntaxHighlighter *hl = new GenericSyntaxHighlighter (src_te, input, mp_hl_attributes.get ());
-  input.close ();
-
-  hl->setDocument (src_te->document ());
-
-  connect (src_te, SIGNAL (cursorPositionChanged ()), this, SLOT (cursor_position_changed ()));
-}
-
-void
-D25TechnologyComponentEditor::cursor_position_changed ()
-{
-  int line = src_te->textCursor ().block ().firstLineNumber () + 1;
-  lnum_label->setText (tl::to_qstring (tl::sprintf (tl::to_string (tr ("Line %d")), line)));
-}
-
-void
-D25TechnologyComponentEditor::commit ()
-{
-  db::D25TechnologyComponent *data = dynamic_cast <db::D25TechnologyComponent *> (tech_component ());
-  if (! data) {
-    return;
-  }
-
-  std::string src = tl::to_string (src_te->toPlainText ());
-
-  //  test-compile before setting it
-  db::D25TechnologyComponent tc;
-  tc.set_src (src);
-  tc.compile_from_source ();
-
-  data->set_src (src);
-}
-
-void
-D25TechnologyComponentEditor::setup ()
-{
-  db::D25TechnologyComponent *data = dynamic_cast <db::D25TechnologyComponent *> (tech_component ());
-  if (! data) {
-    return;
-  }
-
-  src_te->setPlainText (tl::to_qstring (data->src ()));
-}
-
-class D25TechnologyComponentEditorProvider
-  : public lay::TechnologyEditorProvider
-{
-public:
-  virtual lay::TechnologyComponentEditor *create_editor (QWidget *parent) const
-  {
-    return new D25TechnologyComponentEditor (parent);
-  }
-};
-
-static tl::RegisteredClass<lay::TechnologyEditorProvider> editor_decl (new D25TechnologyComponentEditorProvider (), 3100, "d25");
-
-} // namespace lay
-
diff --git a/src/laybasic/laybasic/layD25TechnologyComponent.h b/src/laybasic/laybasic/layD25TechnologyComponent.h
deleted file mode 100644
index 5cdf03df8..000000000
--- a/src/laybasic/laybasic/layD25TechnologyComponent.h
+++ /dev/null
@@ -1,57 +0,0 @@
-
-/*
-
-  KLayout Layout Viewer
-  Copyright (C) 2006-2022 Matthias Koefferlein
-
-  This program is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-
-*/
-
-
-#ifndef HDR_layD25TechnologyComponent
-#define HDR_layD25TechnologyComponent
-
-#include "ui_D25TechnologyComponentEditor.h"
-#include "layTechnology.h"
-#include "layGenericSyntaxHighlighter.h"
-
-#include <memory>
-
-namespace lay {
-
-class D25TechnologyComponentEditor
-  : public lay::TechnologyComponentEditor,
-    public Ui::D25TechnologyComponentEditor
-{
-Q_OBJECT
-
-public:
-  D25TechnologyComponentEditor (QWidget *parent);
-
-  void commit ();
-  void setup ();
-
-private slots:
-  void cursor_position_changed ();
-
-private:
-  std::unique_ptr<lay::GenericSyntaxHighlighterAttributes> mp_hl_attributes, mp_hl_basic_attributes;
-};
-
-}
-
-#endif
-
diff --git a/src/laybasic/laybasic/layParsedLayerSource.h b/src/laybasic/laybasic/layParsedLayerSource.h
index 7bc862d42..e3bbfa511 100644
--- a/src/laybasic/laybasic/layParsedLayerSource.h
+++ b/src/laybasic/laybasic/layParsedLayerSource.h
@@ -35,8 +35,8 @@
 
 namespace db
 {
-  struct LayerProperties;
   class Layout;
+  struct LayerProperties;
 }
 
 namespace lay 
diff --git a/src/laybasic/laybasic/laybasic.pro b/src/laybasic/laybasic/laybasic.pro
index a9cd72e78..ed2625d9d 100644
--- a/src/laybasic/laybasic/laybasic.pro
+++ b/src/laybasic/laybasic/laybasic.pro
@@ -74,8 +74,7 @@ FORMS = \
     NetInfoDialog.ui \
     NetExportDialog.ui \
     SelectCellViewForm.ui \
-    LayoutStatistics.ui \
-    D25TechnologyComponentEditor.ui
+    LayoutStatistics.ui
 
 RESOURCES = \
     laybasicResources.qrc \
@@ -192,7 +191,6 @@ SOURCES = \
     laySelectCellViewForm.cc \
     layLayoutStatisticsForm.cc \
     gsiDeclLayNetlistBrowserDialog.cc \
-    layD25TechnologyComponent.cc \
     layLayoutViewFunctions.cc
 
 HEADERS = \
@@ -300,7 +298,6 @@ HEADERS = \
     layDispatcher.h \
     laySelectCellViewForm.h \
     layLayoutStatisticsForm.h \
-    layD25TechnologyComponent.h \
     layLayoutViewFunctions.h 
 
 INCLUDEPATH += $$TL_INC $$GSI_INC $$DB_INC $$RDB_INC $$LYM_INC
diff --git a/src/lvs/lvs/built-in-macros/lvs_interpreters.lym b/src/lvs/lvs/built-in-macros/lvs_interpreters.lym
index f9f9863f8..24cd20021 100644
--- a/src/lvs/lvs/built-in-macros/lvs_interpreters.lym
+++ b/src/lvs/lvs/built-in-macros/lvs_interpreters.lym
@@ -159,6 +159,11 @@ module LVS
   LVSInterpreter::new(lvs_recipe)
   LVSPlainTextInterpreter::new(lvs_recipe)
 
+  # Creates a new macro category
+  if RBA::Application::instance 
+    RBA::Application::instance.add_macro_category("lvs", "LVS", [ "lvs" ])
+  end
+ 
 end
 </text>
 </klayout-macro>
diff --git a/src/lym/lym/lymMacro.cc b/src/lym/lym/lymMacro.cc
index 8067b67df..429a4fbf2 100644
--- a/src/lym/lym/lymMacro.cc
+++ b/src/lym/lym/lymMacro.cc
@@ -46,6 +46,8 @@
 
 #include <fstream>
 #include <memory>
+#include <string>
+#include <set>
 
 namespace lym
 {
@@ -53,7 +55,7 @@ namespace lym
 // ----------------------------------------------------------------------
 
 Macro::Macro ()
-  : m_modified (true), m_readonly (false), m_autorun (false), m_autorun_default (false), m_autorun_early (false), m_show_in_menu (false), m_is_file (false), mp_parent (0), m_interpreter (None), m_format (Macro::NoFormat)
+  : m_modified (true), m_readonly (false), m_autorun (false), m_autorun_default (false), m_autorun_early (false), m_priority (0), m_show_in_menu (false), m_is_file (false), mp_parent (0), m_interpreter (None), m_format (Macro::NoFormat)
 {
   // .. nothing yet ..
 }
@@ -87,6 +89,7 @@ void Macro::assign (const lym::Macro &other)
   m_autorun = other.m_autorun;
   m_autorun_default = other.m_autorun_default;
   m_autorun_early = other.m_autorun_early;
+  m_priority = other.m_priority;
   m_show_in_menu = other.m_show_in_menu;
   m_shortcut = other.m_shortcut;
   m_format = other.m_format;
@@ -111,6 +114,7 @@ bool Macro::operator== (const Macro &other) const
     m_text == other.m_text &&
     m_autorun == other.m_autorun &&
     m_autorun_early == other.m_autorun_early &&
+    m_priority == other.m_priority &&
     m_show_in_menu == other.m_show_in_menu &&
     m_shortcut == other.m_shortcut &&
     m_interpreter == other.m_interpreter &&
@@ -182,6 +186,7 @@ static tl::XMLStruct<lym::Macro> xml_struct ("klayout-macro",
   tl::make_member (&Macro::doc, &Macro::set_doc, "doc") +
   tl::make_member (&Macro::is_autorun, &Macro::set_autorun, "autorun") +
   tl::make_member (&Macro::is_autorun_early, &Macro::set_autorun_early, "autorun-early") +
+  tl::make_member (&Macro::priority, &Macro::set_priority, "priority") +
   tl::make_member (&Macro::shortcut, &Macro::set_shortcut, "shortcut") +
   tl::make_member (&Macro::show_in_menu, &Macro::set_show_in_menu, "show-in-menu") +
   tl::make_member (&Macro::group_name, &Macro::set_group_name, "group-name") +
@@ -550,19 +555,22 @@ struct PropertyField
   void (lym::Macro::*string_setter) (const std::string &);
   bool (lym::Macro::*bool_getter) () const;
   void (lym::Macro::*bool_setter) (bool);
+  int (lym::Macro::*int_getter) () const;
+  void (lym::Macro::*int_setter) (int);
 };
 
 static PropertyField property_fields[] = {
-  { "description",    &lym::Macro::description, &lym::Macro::set_description,   0, 0 }, 
-  { "prolog",         &lym::Macro::prolog, &lym::Macro::set_prolog,             0, 0 }, 
-  { "epilog",         &lym::Macro::epilog, &lym::Macro::set_epilog,             0, 0 }, 
-  { "version",        &lym::Macro::version, &lym::Macro::set_version,           0, 0 }, 
-  { "autorun",        0, 0,                                                     &lym::Macro::is_autorun, &lym::Macro::set_autorun },
-  { "autorun-early",  0, 0,                                                     &lym::Macro::is_autorun_early, &lym::Macro::set_autorun_early},
-  { "show-in-menu",   0, 0,                                                     &lym::Macro::show_in_menu, &lym::Macro::set_show_in_menu },
-  { "group-name",     &lym::Macro::group_name, &lym::Macro::set_group_name,     0, 0 }, 
-  { "menu-path",      &lym::Macro::menu_path, &lym::Macro::set_menu_path,       0, 0 }, 
-  { "shortcut",       &lym::Macro::shortcut, &lym::Macro::set_shortcut,         0, 0 } 
+  { "description",    &lym::Macro::description, &lym::Macro::set_description,   0, 0,                                                            0, 0 },
+  { "prolog",         &lym::Macro::prolog, &lym::Macro::set_prolog,             0, 0,                                                            0, 0 },
+  { "epilog",         &lym::Macro::epilog, &lym::Macro::set_epilog,             0, 0,                                                            0, 0 },
+  { "version",        &lym::Macro::version, &lym::Macro::set_version,           0, 0,                                                            0, 0 },
+  { "autorun",        0, 0,                                                     &lym::Macro::is_autorun, &lym::Macro::set_autorun,               0, 0 },
+  { "autorun-early",  0, 0,                                                     &lym::Macro::is_autorun_early, &lym::Macro::set_autorun_early,   0, 0 },
+  { "show-in-menu",   0, 0,                                                     &lym::Macro::show_in_menu, &lym::Macro::set_show_in_menu,        0, 0 },
+  { "group-name",     &lym::Macro::group_name, &lym::Macro::set_group_name,     0, 0,                                                            0, 0 },
+  { "menu-path",      &lym::Macro::menu_path, &lym::Macro::set_menu_path,       0, 0,                                                            0, 0 },
+  { "shortcut",       &lym::Macro::shortcut, &lym::Macro::set_shortcut,         0, 0,                                                            0, 0 },
+  { "priority",       0, 0,                                                     0, 0,                                                            &lym::Macro::priority, &lym::Macro::set_priority }
 };
 
 static std::string escape_pta_string (const char *cp) 
@@ -623,6 +631,11 @@ void Macro::sync_text_with_properties ()
       if (v) {
         new_lines.push_back (std::string ("# $") + pf->name);
       }
+    } else if (pf->int_getter) {
+      int v = (this->*(pf->int_getter)) ();
+      if (v) {
+        new_lines.push_back (std::string ("# $") + pf->name + ": " + tl::to_string (v));
+      }
     }
   }
 
@@ -670,6 +683,8 @@ void Macro::sync_properties_with_text ()
       (this->*(pf->string_setter)) (std::string ());
     } else if (pf->bool_setter) {
       (this->*(pf->bool_setter)) (false);
+    } else if (pf->int_setter) {
+      (this->*(pf->int_setter)) (0);
     }
   }
 
@@ -694,6 +709,10 @@ void Macro::sync_properties_with_text ()
             (this->*(pf->string_setter)) (unescape_pta_string (pex.skip ()));
           } else if (pf->bool_setter) {
             (this->*(pf->bool_setter)) (true);
+          } else if (pf->int_setter) {
+            int v = 0;
+            tl::from_string (pex.skip (), v);
+            (this->*(pf->int_setter)) (v);
           }
 
           break;
@@ -765,6 +784,15 @@ void Macro::set_autorun (bool f)
   }
 }
 
+void Macro::set_priority (int p)
+{
+  if (p != m_priority) {
+    m_modified = true;
+    m_priority = p;
+    on_changed ();
+  }
+}
+
 void Macro::set_show_in_menu (bool f)
 {
   if (f != m_show_in_menu) {
@@ -1065,6 +1093,11 @@ MacroCollection::MacroCollection ()
 }
 
 MacroCollection::~MacroCollection ()
+{
+  do_clear ();
+}
+
+void MacroCollection::do_clear ()
 {
   for (iterator m = begin (); m != end (); ++m) {
     delete m->second;
@@ -1513,6 +1546,13 @@ void MacroCollection::scan (const std::string &path)
   }
 }
 
+void MacroCollection::clear ()
+{
+  begin_changes ();
+  do_clear ();
+  on_changed ();
+}
+
 void MacroCollection::erase (lym::Macro *mp)
 {
   for (iterator m = m_macros.begin (); m != m_macros.end (); ++m) {
@@ -1861,30 +1901,78 @@ bool MacroCollection::has_autorun_early () const
   return has_autorun_for (*this, true);
 }
 
-static void autorun_for (lym::MacroCollection &collection, bool early)
+static int collect_priority (lym::MacroCollection &collection, bool early, int from_prio)
 {
+  int p = -1;
+
   for (lym::MacroCollection::child_iterator c = collection.begin_children (); c != collection.end_children (); ++c) {
-    autorun_for (*c->second, early);
+    int pp = collect_priority (*c->second, early, from_prio);
+    if (pp >= from_prio && (p < 0 || pp < p)) {
+      p = pp;
+    }
   }
 
   for (lym::MacroCollection::iterator c = collection.begin (); c != collection.end (); ++c) {
     if (c->second->can_run () && ((early && c->second->is_autorun_early ()) || (!early && c->second->is_autorun () && !c->second->is_autorun_early ()))) {
-      BEGIN_PROTECTED_SILENT
-        c->second->run ();
-        c->second->install_doc ();
-      END_PROTECTED_SILENT
+      int pp = c->second->priority ();
+      if (pp >= from_prio && (p < 0 || pp < p)) {
+        p = pp;
+      }
     }
   }
+
+  return p;
+}
+
+static void autorun_for_prio (lym::MacroCollection &collection, bool early, std::set<std::string> *executed_already, int prio)
+{
+  for (lym::MacroCollection::child_iterator c = collection.begin_children (); c != collection.end_children (); ++c) {
+    autorun_for_prio (*c->second, early, executed_already, prio);
+  }
+
+  for (lym::MacroCollection::iterator c = collection.begin (); c != collection.end (); ++c) {
+
+    if (c->second->priority () == prio && c->second->can_run () && ((early && c->second->is_autorun_early ()) || (!early && c->second->is_autorun () && !c->second->is_autorun_early ()))) {
+
+      if (!executed_already || executed_already->find (c->second->path ()) == executed_already->end ()) {
+
+        BEGIN_PROTECTED_SILENT
+          c->second->run ();
+          c->second->install_doc ();
+        END_PROTECTED_SILENT
+
+        if (executed_already) {
+          executed_already->insert (c->second->path ());
+        }
+
+      }
+
+    }
+
+  }
 }
 
-void MacroCollection::autorun ()
+static void autorun_for (lym::MacroCollection &collection, bool early, std::set<std::string> *executed_already)
 {
-  autorun_for (*this, false);
+  int prio = 0;
+  while (true) {
+    int p = collect_priority (collection, early, prio);
+    if (p < prio) {
+      break;
+    }
+    autorun_for_prio (collection, early, executed_already, p);
+    prio = p + 1;
+  }
 }
 
-void MacroCollection::autorun_early ()
+void MacroCollection::autorun (std::set<std::string> *already_executed)
 {
-  autorun_for (*this, true);
+  autorun_for (*this, false, already_executed);
+}
+
+void MacroCollection::autorun_early (std::set<std::string> *already_executed)
+{
+  autorun_for (*this, true, already_executed);
 }
 
 void MacroCollection::dump (int l)
diff --git a/src/lym/lym/lymMacro.h b/src/lym/lym/lymMacro.h
index 396bdbee3..619be68a6 100644
--- a/src/lym/lym/lymMacro.h
+++ b/src/lym/lym/lymMacro.h
@@ -430,6 +430,20 @@ public:
    */
   void set_autorun_early (bool f);
 
+  /**
+   *  @brief Gets the priority of the macro in autorun and autorun-early mode
+   *  0 is the first priority, -1 means "never execute".
+   */
+  int priority () const
+  {
+    return m_priority;
+  }
+
+  /**
+   *  @brief Sets the priority
+   */
+  void set_priority (int p);
+
   /**
    *  @brief Gets a value indicating whether the macro shall be shown in the menu
    */
@@ -596,6 +610,7 @@ private:
   bool m_autorun;
   bool m_autorun_default;
   bool m_autorun_early;
+  int m_priority;
   bool m_show_in_menu;
   std::string m_group_name;
   std::string m_menu_path;
@@ -845,6 +860,12 @@ public:
    */
   void add_unspecific (lym::Macro *m);
 
+  /**
+   *  @brief Empties the collection
+   *  Note: only the unspecific on_changed event is generated.
+   */
+  void clear ();
+
   /**
    *  @brief Erases the given macro from the list
    *  
@@ -995,7 +1016,7 @@ public:
   /**
    *  @brief Runs all macros marked with auto-run
    */
-  void autorun ();
+  void autorun (std::set<std::string> *already_executed = 0);
 
   /**
    *  @brief Returns true, if the collection has an early autorun macro
@@ -1005,7 +1026,7 @@ public:
   /**
    *  @brief Runs all macros marked with early auto-run
    */
-  void autorun_early ();
+  void autorun_early (std::set<std::string> *already_executed = 0);
 
   /**
    *  @brief Redo the scan (will add new files or folders)
@@ -1129,6 +1150,8 @@ private:
     m_readonly = f;
   }
 
+  void do_clear ();
+
   //  no copying
   MacroCollection (const MacroCollection &d);
   MacroCollection &operator= (const MacroCollection &d);
diff --git a/src/plugins/tools/view_25d/lay_plugin/D25View.ui b/src/plugins/tools/view_25d/lay_plugin/D25View.ui
index 75301397d..a38817f62 100644
--- a/src/plugins/tools/view_25d/lay_plugin/D25View.ui
+++ b/src/plugins/tools/view_25d/lay_plugin/D25View.ui
@@ -59,6 +59,42 @@
       <property name="bottomMargin">
        <number>0</number>
       </property>
+      <item>
+       <widget class="QToolButton" name="rerun_button">
+        <property name="enabled">
+         <bool>false</bool>
+        </property>
+        <property name="toolTip">
+         <string>Execute script again</string>
+        </property>
+        <property name="text">
+         <string>...</string>
+        </property>
+        <property name="icon">
+         <iconset resource="../../../../lay/lay/layResources.qrc">
+          <normaloff>:/run.png</normaloff>:/run.png</iconset>
+        </property>
+        <property name="autoRaise">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <spacer name="horizontalSpacer_4">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeType">
+         <enum>QSizePolicy::Fixed</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>10</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
       <item>
        <widget class="QSlider" name="zoom_slider">
         <property name="sizePolicy">
@@ -343,6 +379,9 @@
    </item>
    <item>
     <widget class="QStackedWidget" name="gl_stack">
+     <property name="currentIndex">
+      <number>2</number>
+     </property>
      <widget class="QWidget" name="page">
       <layout class="QVBoxLayout" name="verticalLayout">
        <property name="leftMargin">
@@ -358,7 +397,60 @@
         <number>0</number>
        </property>
        <item>
-        <widget class="lay::D25ViewWidget" name="d25_view"/>
+        <widget class="QFrame" name="frame_3">
+         <property name="frameShape">
+          <enum>QFrame::NoFrame</enum>
+         </property>
+         <property name="frameShadow">
+          <enum>QFrame::Plain</enum>
+         </property>
+         <layout class="QVBoxLayout" name="verticalLayout_3">
+          <property name="leftMargin">
+           <number>0</number>
+          </property>
+          <property name="topMargin">
+           <number>0</number>
+          </property>
+          <property name="rightMargin">
+           <number>0</number>
+          </property>
+          <property name="bottomMargin">
+           <number>0</number>
+          </property>
+          <item>
+           <widget class="QSplitter" name="splitter">
+            <property name="orientation">
+             <enum>Qt::Horizontal</enum>
+            </property>
+            <widget class="lay::D25ViewWidget" name="d25_view">
+             <property name="sizePolicy">
+              <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+               <horstretch>1</horstretch>
+               <verstretch>0</verstretch>
+              </sizepolicy>
+             </property>
+            </widget>
+            <widget class="QListWidget" name="material_list">
+             <property name="sizePolicy">
+              <sizepolicy hsizetype="Preferred" vsizetype="Expanding">
+               <horstretch>0</horstretch>
+               <verstretch>0</verstretch>
+              </sizepolicy>
+             </property>
+             <property name="selectionMode">
+              <enum>QAbstractItemView::ExtendedSelection</enum>
+             </property>
+             <property name="spacing">
+              <number>0</number>
+             </property>
+             <property name="uniformItemSizes">
+              <bool>true</bool>
+             </property>
+            </widget>
+           </widget>
+          </item>
+         </layout>
+        </widget>
        </item>
       </layout>
      </widget>
@@ -419,6 +511,21 @@
        </item>
       </layout>
      </widget>
+     <widget class="QWidget" name="page_3">
+      <layout class="QVBoxLayout" name="verticalLayout_4">
+       <item>
+        <widget class="QLabel" name="empty_label">
+         <property name="text">
+          <string>In order to use the 2.5d view you will need a script which generates the view.&lt;br/&gt;
+See here for more information: &lt;a href=&quot;int:/about/25d_view.xml&quot;&gt;The 2.5d View&lt;/a&gt;.</string>
+         </property>
+         <property name="alignment">
+          <set>Qt::AlignCenter</set>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </widget>
     </widget>
    </item>
    <item>
@@ -482,6 +589,36 @@
     </widget>
    </item>
   </layout>
+  <action name="select_all_action">
+   <property name="text">
+    <string>Select All</string>
+   </property>
+  </action>
+  <action name="unselect_all_action">
+   <property name="text">
+    <string>Unselect All</string>
+   </property>
+  </action>
+  <action name="show_all_action">
+   <property name="text">
+    <string>Show All</string>
+   </property>
+  </action>
+  <action name="hide_all_action">
+   <property name="text">
+    <string>Hide All</string>
+   </property>
+  </action>
+  <action name="show_selected_action">
+   <property name="text">
+    <string>Show Selected</string>
+   </property>
+  </action>
+  <action name="hide_selected_action">
+   <property name="text">
+    <string>Hide Selected</string>
+   </property>
+  </action>
  </widget>
  <customwidgets>
   <customwidget>
@@ -510,5 +647,37 @@
     </hint>
    </hints>
   </connection>
+  <connection>
+   <sender>select_all_action</sender>
+   <signal>triggered()</signal>
+   <receiver>material_list</receiver>
+   <slot>selectAll()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>-1</x>
+     <y>-1</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>716</x>
+     <y>336</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>unselect_all_action</sender>
+   <signal>triggered()</signal>
+   <receiver>material_list</receiver>
+   <slot>clearSelection()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>-1</x>
+     <y>-1</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>716</x>
+     <y>336</y>
+    </hint>
+   </hints>
+  </connection>
  </connections>
 </ui>
diff --git a/src/plugins/tools/view_25d/lay_plugin/built-in-macros/_d25_engine.rb b/src/plugins/tools/view_25d/lay_plugin/built-in-macros/_d25_engine.rb
new file mode 100644
index 000000000..f1114cc0b
--- /dev/null
+++ b/src/plugins/tools/view_25d/lay_plugin/built-in-macros/_d25_engine.rb
@@ -0,0 +1,288 @@
+# $autorun-early
+# $priority: 1
+
+require 'pathname'
+
+module D25
+
+  class D25ZInfo
+
+    attr_accessor :layer, :zstart, :zstop, :display
+
+    def initialize(_layer, _zstart, _zstop, _display)
+      self.layer = _layer
+      self.zstart = _zstart
+      self.zstop = _zstop
+      self.display = _display
+    end
+
+  end
+
+  class D25Display
+
+    attr_accessor :fill, :frame, :like, :name
+
+    def initialize
+      self.fill = nil
+      self.frame = nil
+      self.like = nil
+      self.name = nil
+    end
+
+    def set_fill(arg)
+      if !arg.is_a?(0xffffff.class)
+        raise("'fill' must be a color value (an integer)")
+      end
+      self.fill = arg
+    end
+
+    def set_frame(arg)
+      if !arg.is_a?(0xffffff.class)
+        raise("'frame' must be a color value (an integer)")
+      end
+      self.frame = arg
+    end
+
+    def set_color(arg)
+      if !arg.is_a?(0xffffff.class)
+        raise("'color' must be a color value (an integer)")
+      end
+      self.fill = arg
+      self.frame = nil
+    end
+
+    def set_like(arg)
+      li = nil
+      if arg.is_a?(String)
+        li = RBA::LayerInfo::from_string(arg)
+      elsif arg.is_a?(RBA::LayerInfo)
+        li = arg
+      else
+        raise("'like' must be a string or LayerInfo object")
+      end
+      self.like = li
+    end
+
+  end
+
+  # The D25 engine
+  
+  class D25Engine < DRC::DRCEngine
+  
+    def initialize
+
+      super
+
+      @current_z = 0.0
+      @zstack = []
+
+      # clip to layout view
+      if ! RBA::LayoutView::current
+        raise "No layout loaded for running 2.5d view on"
+      end 
+
+      self.region_overlap(RBA::LayoutView::current.box)
+
+    end
+
+    def z(*args)
+
+      self._context("z") do
+
+        layer = nil
+        zstart = nil
+        zstop = nil
+        height = nil
+        display = D25Display::new
+
+        args.each do |a|
+
+          if a.is_a?(Range)
+
+            zstart = a.min
+            zstop = a.max
+
+          elsif a.is_a?(DRC::DRCLayer)
+
+            if layer
+              raise("Duplicate layer argument")
+            end
+            layer = a
+            if ! layer.data.is_a?(RBA::Region) && ! layer.data.is_a?(RBA::Edges) && ! layer.data.is_a?(RBA::EdgePairs)
+              raise("Expected a polygon, edge or edge pair layer")
+            end
+
+          elsif a.is_a?(1.class) || a.is_a?(1.0.class)
+
+            if height
+              raise("Duplicate height specification")
+            end
+            height = a
+
+          elsif a.is_a?(Hash)
+
+            if a[:height]
+              if height
+                raise("Duplicate height specification")
+              end
+              height = a[:height]
+            end
+
+            if a[:zstart]
+              if zstart
+                raise("Duplicate zstart specification")
+              end
+              zstart = a[:zstart]
+            end
+
+            if a[:zstop]
+              if zstop
+                raise("Duplicate zstop specification")
+              end
+              zstop = a[:zstop]
+            end  
+
+            a[:color] && display.set_color(a[:color])
+            a[:frame] && display.set_frame(a[:frame])
+            a[:fill] && display.set_fill(a[:fill])
+            a[:like] && display.set_like(a[:like])
+
+            if a[:name]
+              display.name = a[:name].to_s
+            end
+
+            invalid_keys = a.keys.select { |k| ![ :height, :zstart, :zstop, :color, :frame, :fill, :like, :name ].member?(k) }
+            if invalid_keys.size > 0
+              raise("Keyword argument(s) not understood: #{invalid_keys.collect(&:to_s).join(',')}")
+            end
+
+          else
+            raise("Argument not understood: #{a.inspect}")
+          end
+
+        end
+
+        if ! zstart
+          zstart = @current_z
+        end
+        if ! zstop && ! height
+          raise("Either height or zstop must be specified")
+        elsif zstop && height
+          raise("Either height or zstop must be specified, not both")
+        end
+        if height
+          zstop = zstart + height
+        end
+        @current_z = zstop
+
+        if ! layer
+          raise("No layer specified")
+        end
+
+        info = D25ZInfo::new(layer, zstart, zstop, @display || display)
+        @zstack << info
+
+        return info
+
+      end
+
+    end
+    
+    def zz(*args, &block)
+
+      begin
+
+        display = D25Display::new
+        @display = display
+
+        args.each do |a|
+
+          if a.is_a?(D25ZInfo)
+
+            @zstack.each do |z|
+              if z == a
+                z.display = display
+              end
+            end
+
+          elsif a.is_a?(Hash)
+
+            a[:color] && display.set_color(a[:color])
+            a[:frame] && display.set_frame(a[:frame])
+            a[:fill] && display.set_fill(a[:fill])
+            a[:like] && display.set_like(a[:like])
+
+            if a[:name]
+              display.name = a[:name].to_s
+            end
+
+            invalid_keys = a.keys.select { |k| ![ :fill, :frame, :color, :hollow, :like, :name ].member?(k) }
+            if invalid_keys.size > 0
+              raise("Keyword argument(s) not understood: #{invalid_keys.collect(&:to_s).join(',')}")
+            end
+
+          else
+            raise("Argument not understood: #{a.inspect}")
+          end
+              
+        end
+
+        block && yield
+
+      ensure
+        @display = nil
+      end
+
+    end
+
+    def _check
+
+      if @zstack.empty?
+        raise("No z calls made in 2.5d script")
+      end
+
+    end
+
+    def _finish(final = true)
+
+      super(final)
+
+      if final
+
+        view = RBA::LayoutView::current.open_d25_view
+
+        begin
+
+          view.begin(self._generator)
+
+          displays = {}
+
+          @zstack.each do |z|
+            (displays[z.display.object_id] ||= []) << z
+          end
+
+          displays.each do |k,zz|
+            display = zz[0].display
+            view.open_display(display.frame, display.fill, display.like, display.name)
+            zz.each do |z|
+              view.entry(z.layer.data, self.dbu, z.zstart, z.zstop)
+            end
+            view.close_display
+          end
+          
+          view.finish
+
+        rescue => ex
+          view.clear
+          view.close
+          raise ex
+        end
+
+      end
+
+    end
+
+  end
+ 
+end
+
diff --git a/src/plugins/tools/view_25d/lay_plugin/built-in-macros/d25_install.lym b/src/plugins/tools/view_25d/lay_plugin/built-in-macros/d25_install.lym
new file mode 100644
index 000000000..ead33cc20
--- /dev/null
+++ b/src/plugins/tools/view_25d/lay_plugin/built-in-macros/d25_install.lym
@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="utf-8"?>
+<klayout-macro>
+ <description/>
+ <version/>
+ <category/>
+ <prolog/>
+ <epilog/>
+ <doc/>
+ <autorun>true</autorun>
+ <autorun-early>false</autorun-early>
+ <shortcut/>
+ <show-in-menu>false</show-in-menu>
+ <group-name/>
+ <menu-path/>
+ <interpreter>ruby</interpreter>
+ <dsl-interpreter-name/>
+ <text>
+module D25
+
+  # Installs the home menu entries (needs to be done on autorun, not autorun-early)
+
+  if RBA::Application::instance &amp;&amp; RBA::Application::instance.main_window
+
+    cat = "d25"
+    name = "2.5d"
+
+    mw = RBA::Application::instance.main_window
+    mw.menu.insert_menu("tools_menu.verification_group+", "d25", "2.5d View")
+
+    @new_action = RBA::Action::new
+    @new_action.title = "New #{name} Script"
+    @new_action.on_triggered do
+      mw.show_macro_editor(cat, true) 
+    end
+
+    mw.menu.insert_item("tools_menu.#{cat}.end", "new_script", @new_action)
+
+    @edit_action = RBA::Action::new
+    @edit_action.title = "Edit #{name} Script"
+    @edit_action.on_triggered do
+      mw.show_macro_editor(cat, false) 
+    end
+
+    mw.menu.insert_item("tools_menu.#{cat}.end", "edit_script", @edit_action)
+
+    @open_action = RBA::Action::new
+    @open_action.title = "Open Window"
+    @open_action.on_triggered do
+      if ! RBA::LayoutView::current
+        RBA::MessageBox::critical("Error", "No layout loaded for running 2.5d view on", RBA::MessageBox::Ok)
+      else 
+        RBA::LayoutView::current.open_d25_view
+      end
+    end
+
+    mw.menu.insert_item("tools_menu.#{cat}.end", "open_window", @open_action)
+
+  end
+
+end
+</text>
+</klayout-macro>
+
diff --git a/src/plugins/tools/view_25d/lay_plugin/built-in-macros/d25_interpreters.lym b/src/plugins/tools/view_25d/lay_plugin/built-in-macros/d25_interpreters.lym
new file mode 100644
index 000000000..86d7d954d
--- /dev/null
+++ b/src/plugins/tools/view_25d/lay_plugin/built-in-macros/d25_interpreters.lym
@@ -0,0 +1,171 @@
+<?xml version="1.0" encoding="utf-8"?>
+<klayout-macro>
+ <description/>
+ <version/>
+ <category/>
+ <prolog/>
+ <epilog/>
+ <doc/>
+ <autorun>false</autorun>
+ <autorun-early>true</autorun-early>
+ <shortcut/>
+ <show-in-menu>false</show-in-menu>
+ <group-name/>
+ <menu-path/>
+ <interpreter>ruby</interpreter>
+ <dsl-interpreter-name/>
+ <text>
+module D25
+
+  class D25Executable &lt; RBA::Executable
+
+    def initialize(macro, generator)
+
+      @d25 = D25Engine::new
+      @d25._generator = generator
+
+      @macro = macro
+
+    end
+
+    def execute
+
+      @d25._start("D25: " + @macro.path)
+
+      # Set a debugger scope so that our errors end up with the debugger set to the D25's line
+      RBA::MacroExecutionContext::set_debugger_scope(@macro.path)
+
+      begin
+
+        # No verbosity set in d25 engine - we cannot use the engine's logger 
+        RBA::Logger::verbosity &gt;= 10 &amp;&amp; RBA::Logger::info("Running #{@macro.path}")
+        @d25.instance_eval(@macro.text, @macro.path)
+
+      rescue =&gt; ex
+
+        @d25.error("In #{@macro.path}: #{ex.to_s}")
+        RBA::MacroExecutionContext::ignore_next_exception
+        raise ex
+
+      end
+
+      @d25._check
+
+      nil
+
+    end
+
+    def cleanup
+
+      # Remove the debugger scope
+      RBA::MacroExecutionContext::remove_debugger_scope
+
+      # cleans up and creates layout and report views
+      @d25._finish
+
+    end
+
+  end
+  
+  # A DSL implementation for a D25 language (XML format)
+  class D25Interpreter &lt; RBA::MacroInterpreter
+  
+    # Constructor
+    def initialize(recipe)
+
+      @recipe = recipe
+
+      # Make the DSL use ruby syntax highlighting
+      self.syntax_scheme = "ruby"
+      self.suffix = "lyd25"
+      self.debugger_scheme = RBA::MacroInterpreter::RubyDebugger
+      self.storage_scheme = RBA::MacroInterpreter::MacroFormat
+      self.description = "D25"
+
+      # Registers the new interpreter
+      register("d25-dsl-xml")
+
+      # create a template for the macro editor:
+      create_template(":/d25-templates/d25.lym")
+
+      # if available, create a menu branch
+      if RBA::Application::instance &amp;&amp; RBA::Application::instance.main_window
+        mw = RBA::Application::instance.main_window
+        mw.menu.insert_menu("tools_menu.verification_group+", "d25", "2.5d View")
+      end
+
+    end
+    
+    # Implements the execute method
+    def executable(macro)
+      D25Executable::new(macro, @recipe.generator("script" => macro.path))
+    end
+    
+  end
+  
+  # A DSL implementation for a D25 language (Plain text format)
+  class D25PlainTextInterpreter &lt; RBA::MacroInterpreter
+  
+    # Constructor
+    def initialize(recipe)
+
+      @recipe = recipe
+
+      # Make the DSL use ruby syntax highlighting
+      self.syntax_scheme = "ruby"
+      self.suffix = "d25"
+      self.debugger_scheme = RBA::MacroInterpreter::RubyDebugger
+      self.storage_scheme = RBA::MacroInterpreter::PlainTextWithHashAnnotationsFormat
+      self.description = "D25 (Text)"
+
+      # Registers the new interpreter
+      register("d25-dsl")
+
+    end
+    
+    # Implements the execute method
+    def executable(macro)
+      D25Executable::new(macro, @recipe.generator("script" => macro.path))
+    end
+    
+  end
+  
+  # A recipe implementation allowing the D25 run to be redone
+  class D25Recipe &lt; RBA::Recipe
+
+    def initialize
+      super("d25", "D25 recipe")
+    end
+
+    def executable(params)
+
+      script = params["script"]
+      if ! script
+        return
+      end
+
+      macro = RBA::Macro::macro_by_path(script)
+      macro || raise("Can't find D25 script #{script} - unable to re-run")
+
+      D25Executable::new(macro, self.generator("script" => script))
+      
+    end
+
+  end
+  
+  # Register the recipe
+  d25_recipe = D25Recipe::new
+ 
+  # Register the new interpreters
+  D25Interpreter::new(d25_recipe)
+  D25PlainTextInterpreter::new(d25_recipe)
+
+  # Creates a new macro category
+  if RBA::Application::instance 
+    RBA::Application::instance.add_macro_category("d25", "2.5d View", [ "d25" ])
+  end
+ 
+end
+</text>
+</klayout-macro>
+
diff --git a/src/plugins/tools/view_25d/lay_plugin/gsiDeclLayD25View.cc b/src/plugins/tools/view_25d/lay_plugin/gsiDeclLayD25View.cc
new file mode 100644
index 000000000..ea7bc880e
--- /dev/null
+++ b/src/plugins/tools/view_25d/lay_plugin/gsiDeclLayD25View.cc
@@ -0,0 +1,96 @@
+
+/*
+
+  KLayout Layout Viewer
+  Copyright (C) 2006-2022 Matthias Koefferlein
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+#include "gsiDecl.h"
+#include "gsiDeclBasic.h"
+
+#include "layD25View.h"
+#include "layLayoutView.h"
+
+#include "dbLayerProperties.h"
+#include "dbRegion.h"
+
+#include <limits>
+
+#if defined(HAVE_QTBINDINGS)
+
+#  include "gsiQtGuiExternals.h"
+#  include "gsiQtWidgetsExternals.h"
+
+FORCE_LINK_GSI_QTGUI
+FORCE_LINK_GSI_QTWIDGETS // for Qt5
+
+#else
+# define QT_EXTERNAL_BASE(x)
+#endif
+
+namespace gsi
+{
+
+static lay::D25View *open_d25_view (lay::LayoutView *view)
+{
+  return lay::D25View::open (view);
+}
+
+ClassExt<lay::LayoutView> decl_LayoutViewExt (
+  gsi::method_ext ("open_d25_view", &open_d25_view,
+    "@brief Opens the 2.5d view window and returns a reference to the D25View object.\n"
+    "This method has been introduced in version 0.28.\n"
+  )
+);
+
+Class<lay::D25View> decl_D25View (QT_EXTERNAL_BASE (QDialog) "lay", "D25View",
+  gsi::method ("clear", &lay::D25View::clear,
+    "@brief Clears all display entries in the view"
+  ) +
+  gsi::method ("begin", &lay::D25View::begin, gsi::arg ("generator"),
+    "@brief Initiates delivery of display groups"
+  ) +
+  gsi::method ("open_display", &lay::D25View::open_display, gsi::arg ("frame_color"), gsi::arg ("fill_color"), gsi::arg ("like"), gsi::arg ("name"),
+    "@brief Creates a new display group"
+  ) +
+  gsi::method ("entry", &lay::D25View::entry, gsi::arg ("data"), gsi::arg ("dbu"), gsi::arg ("zstart"), gsi::arg ("zstop"),
+    "@brief Creates a new display entry in the group opened with \\open_display"
+  ) +
+  gsi::method ("entry", &lay::D25View::entry_edge, gsi::arg ("data"), gsi::arg ("dbu"), gsi::arg ("zstart"), gsi::arg ("zstop"),
+    "@brief Creates a new display entry in the group opened with \\open_display"
+  ) +
+  gsi::method ("entry", &lay::D25View::entry_edge_pair, gsi::arg ("data"), gsi::arg ("dbu"), gsi::arg ("zstart"), gsi::arg ("zstop"),
+    "@brief Creates a new display entry in the group opened with \\open_display"
+  ) +
+  gsi::method ("close_display", &lay::D25View::close_display,
+    "@brief Finishes the display group"
+  ) +
+  gsi::method ("finish", &lay::D25View::finish,
+    "@brief Finishes the view - call this after the display groups have been created"
+  ) +
+  gsi::method ("close", &lay::D25View::close,
+    "@brief Closes the view"
+  ),
+  "@brief The 2.5d View Dialog\n"
+  "\n"
+  "This class is used internally to implement the 2.5d feature.\n"
+  "\n"
+  "This class has been introduced in version 0.28."
+);
+
+}
diff --git a/src/plugins/tools/view_25d/lay_plugin/layD25Plugin.cc b/src/plugins/tools/view_25d/lay_plugin/layD25Plugin.cc
index e3a12080d..c6830127c 100644
--- a/src/plugins/tools/view_25d/lay_plugin/layD25Plugin.cc
+++ b/src/plugins/tools/view_25d/lay_plugin/layD25Plugin.cc
@@ -52,10 +52,9 @@ public:
     return 0;
   }
 
-  virtual void get_menu_entries (std::vector<lay::MenuEntry> &menu_entries) const
+  virtual void get_menu_entries (std::vector<lay::MenuEntry> & /*menu_entries*/) const
   {
-    lay::PluginDeclaration::get_menu_entries (menu_entries);
-    menu_entries.push_back (lay::menu_item ("lay::d25_view", "d25_view:edit", "tools_menu.post_verification_group", tl::to_string (QObject::tr ("2.5d View - experimental"))));
+    // .. nothing yet ..
   }
 
   virtual bool configure (const std::string & /*name*/, const std::string & /*value*/)
diff --git a/src/plugins/tools/view_25d/lay_plugin/layD25Resources.qrc b/src/plugins/tools/view_25d/lay_plugin/layD25Resources.qrc
new file mode 100644
index 000000000..be37f46fe
--- /dev/null
+++ b/src/plugins/tools/view_25d/lay_plugin/layD25Resources.qrc
@@ -0,0 +1,10 @@
+<RCC>
+    <qresource prefix="/built-in-macros">
+        <file alias="_d25_engine.rb">built-in-macros/_d25_engine.rb</file>
+        <file alias="d25_interpreters.lym">built-in-macros/d25_interpreters.lym</file>
+        <file alias="d25_install.lym">built-in-macros/d25_install.lym</file>
+    </qresource>
+    <qresource prefix="/d25-templates">
+        <file alias="d25.lym">templates/d25.lym</file>
+    </qresource>
+</RCC>
diff --git a/src/plugins/tools/view_25d/lay_plugin/layD25View.cc b/src/plugins/tools/view_25d/lay_plugin/layD25View.cc
index af10a8621..019dedecd 100644
--- a/src/plugins/tools/view_25d/lay_plugin/layD25View.cc
+++ b/src/plugins/tools/view_25d/lay_plugin/layD25View.cc
@@ -20,6 +20,8 @@
 
 */
 
+#include "tlExceptions.h"
+#include "tlRecipe.h"
 
 #include "layD25View.h"
 #include "layLayoutView.h"
@@ -29,13 +31,17 @@
 
 #include <stdio.h>
 
+#include <QFontMetrics>
+
 namespace lay
 {
 
 const double initial_elevation = 15.0;
 
 D25View::D25View (lay::Dispatcher *root, lay::LayoutView *view)
-  : lay::Browser (root, view, "d25_view")
+  : lay::Browser (root, view, "d25_view"),
+    dm_rerun_macro (this, &D25View::rerun_macro),
+    dm_fit (this, &D25View::fit)
 {
   mp_ui = new Ui::D25View ();
   mp_ui->setupUi (this);
@@ -43,26 +49,52 @@ D25View::D25View (lay::Dispatcher *root, lay::LayoutView *view)
   mp_ui->d25_view->setFocusPolicy (Qt::StrongFocus);
   mp_ui->d25_view->setFocus ();
 
-  connect (mp_ui->fit_back, SIGNAL (clicked ()), this, SLOT (fit_button_clicked ()));
-  connect (mp_ui->fit_front, SIGNAL (clicked ()), this, SLOT (fit_button_clicked ()));
-  connect (mp_ui->fit_left, SIGNAL (clicked ()), this, SLOT (fit_button_clicked ()));
-  connect (mp_ui->fit_right, SIGNAL (clicked ()), this, SLOT (fit_button_clicked ()));
-  connect (mp_ui->fit_top, SIGNAL (clicked ()), this, SLOT (fit_button_clicked ()));
-  connect (mp_ui->fit_bottom, SIGNAL (clicked ()), this, SLOT (fit_button_clicked ()));
-  connect (mp_ui->zoom_slider, SIGNAL (valueChanged (int)), this, SLOT (scale_slider_changed (int)));
-  connect (mp_ui->vzoom_slider, SIGNAL (valueChanged (int)), this, SLOT (vscale_slider_changed (int)));
-  connect (mp_ui->zoom_factor, SIGNAL (editingFinished ()), this, SLOT (scale_value_edited ()));
-  connect (mp_ui->vzoom_factor, SIGNAL (editingFinished ()), this, SLOT (vscale_value_edited ()));
-  connect (mp_ui->d25_view, SIGNAL (scale_factor_changed (double)), this, SLOT (scale_factor_changed (double)));
-  connect (mp_ui->d25_view, SIGNAL (vscale_factor_changed (double)), this, SLOT (vscale_factor_changed (double)));
-  connect (mp_ui->d25_view, SIGNAL (init_failed ()), this, SLOT (init_failed ()));
+  connect (mp_ui->fit_back, SIGNAL (clicked()), this, SLOT (fit_button_clicked()));
+  connect (mp_ui->fit_front, SIGNAL (clicked()), this, SLOT (fit_button_clicked()));
+  connect (mp_ui->fit_left, SIGNAL (clicked()), this, SLOT (fit_button_clicked()));
+  connect (mp_ui->fit_right, SIGNAL (clicked()), this, SLOT (fit_button_clicked()));
+  connect (mp_ui->fit_top, SIGNAL (clicked()), this, SLOT (fit_button_clicked()));
+  connect (mp_ui->fit_bottom, SIGNAL (clicked()), this, SLOT (fit_button_clicked()));
+  connect (mp_ui->zoom_slider, SIGNAL (valueChanged(int)), this, SLOT (scale_slider_changed(int)));
+  connect (mp_ui->vzoom_slider, SIGNAL (valueChanged(int)), this, SLOT (vscale_slider_changed(int)));
+  connect (mp_ui->zoom_factor, SIGNAL (editingFinished()), this, SLOT (scale_value_edited()));
+  connect (mp_ui->vzoom_factor, SIGNAL (editingFinished()), this, SLOT (vscale_value_edited()));
+  connect (mp_ui->d25_view, SIGNAL (scale_factor_changed(double)), this, SLOT (scale_factor_changed(double)));
+  connect (mp_ui->d25_view, SIGNAL (vscale_factor_changed(double)), this, SLOT (vscale_factor_changed(double)));
+  connect (mp_ui->d25_view, SIGNAL (init_failed()), this, SLOT (init_failed()));
+  connect (mp_ui->rerun_button, SIGNAL (clicked()), this, SLOT (rerun_button_pressed()));
+  connect (mp_ui->hide_all_action, SIGNAL (triggered()), this, SLOT (hide_all_triggered()));
+  connect (mp_ui->hide_selected_action, SIGNAL (triggered()), this, SLOT (hide_selected_triggered()));
+  connect (mp_ui->show_all_action, SIGNAL (triggered()), this, SLOT (show_all_triggered()));
+  connect (mp_ui->show_selected_action, SIGNAL (triggered()), this, SLOT (show_selected_triggered()));
 
-  mp_ui->gl_stack->setCurrentIndex (0);
+  mp_ui->gl_stack->setCurrentIndex (2);
+  mp_ui->rerun_button->setEnabled (false);
 
   lay::activate_help_links (mp_ui->doc_label);
+  lay::activate_help_links (mp_ui->empty_label);
 
   view->cellviews_changed_event.add (this, &D25View::cellviews_changed);
   view->layer_list_changed_event.add (this, &D25View::layer_properties_changed);
+
+  QPalette palette = mp_ui->material_list->palette ();
+  palette.setColor (QPalette::Base, Qt::black);
+  palette.setColor (QPalette::Text, Qt::white);
+  mp_ui->material_list->setPalette (palette);
+
+  QFont font = mp_ui->material_list->font ();
+  font.setWeight (QFont::Bold);
+  mp_ui->material_list->setFont (font);
+
+  mp_ui->material_list->addAction (mp_ui->select_all_action);
+  mp_ui->material_list->addAction (mp_ui->unselect_all_action);
+  mp_ui->material_list->addAction (mp_ui->show_all_action);
+  mp_ui->material_list->addAction (mp_ui->show_selected_action);
+  mp_ui->material_list->addAction (mp_ui->hide_all_action);
+  mp_ui->material_list->addAction (mp_ui->hide_selected_action);
+  mp_ui->material_list->setContextMenuPolicy (Qt::ActionsContextMenu);
+
+  connect (mp_ui->material_list, SIGNAL (itemChanged (QListWidgetItem *)), this, SLOT (material_item_changed (QListWidgetItem *)));
 }
 
 D25View::~D25View ()
@@ -84,7 +116,7 @@ D25View::cellviews_changed ()
 void
 D25View::layer_properties_changed (int)
 {
-  mp_ui->d25_view->refresh_view ();
+  //  .. nothing yet ..
 }
 
 void
@@ -113,6 +145,164 @@ D25View::menu_activated (const std::string &symbol)
   }
 }
 
+D25View *
+D25View::open (lay::LayoutView *view)
+{
+  D25View *d25_view = view->get_plugin<lay::D25View> ();
+  if (d25_view) {
+
+    d25_view->show ();
+    d25_view->activateWindow ();
+    d25_view->raise ();
+
+    try {
+      d25_view->activate ();
+    } catch (...) {
+      d25_view->deactivate ();
+      throw;
+    }
+
+  }
+
+  return d25_view;
+}
+
+void
+D25View::close ()
+{
+  hide ();
+}
+
+void
+D25View::clear ()
+{
+  if (! mp_ui->d25_view->has_error ()) {
+    mp_ui->gl_stack->setCurrentIndex (2);
+    mp_ui->d25_view->clear ();
+  }
+
+  mp_ui->rerun_button->setEnabled (false);
+  m_generator.clear ();
+}
+
+void
+D25View::begin (const std::string &generator)
+{
+  clear ();
+
+  if (! mp_ui->d25_view->has_error ()) {
+    m_generator = generator;
+  }
+}
+
+void
+D25View::open_display (const color_t *frame_color, const color_t *fill_color, const db::LayerProperties *like, const std::string *name)
+{
+  if (! mp_ui->d25_view->has_error ()) {
+    mp_ui->d25_view->open_display (frame_color, fill_color, like, name);
+  }
+}
+
+void
+D25View::close_display ()
+{
+  if (! mp_ui->d25_view->has_error ()) {
+    mp_ui->d25_view->close_display ();
+  }
+}
+
+void
+D25View::entry (const db::Region &data, double dbu, double zstart, double zstop)
+{
+  if (! mp_ui->d25_view->has_error ()) {
+    mp_ui->d25_view->entry (data, dbu, zstart, zstop);
+  }
+}
+
+void
+D25View::entry_edge (const db::Edges &data, double dbu, double zstart, double zstop)
+{
+  if (! mp_ui->d25_view->has_error ()) {
+    mp_ui->d25_view->entry (data, dbu, zstart, zstop);
+  }
+}
+
+void
+D25View::entry_edge_pair (const db::EdgePairs &data, double dbu, double zstart, double zstop)
+{
+  if (! mp_ui->d25_view->has_error ()) {
+    mp_ui->d25_view->entry (data, dbu, zstart, zstop);
+  }
+}
+
+static void layer_info_to_item (const lay::D25ViewWidget::LayerInfo &info, QListWidgetItem *item, size_t index, QSize icon_size)
+{
+  if (info.has_name) {
+    item->setText (tl::to_qstring (info.name));
+  } else {
+    item->setText (tl::to_qstring ("#" + tl::to_string (index + 1)));
+  }
+
+  QImage img (icon_size, QImage::Format_ARGB32);
+  img.fill (QColor (floor (info.fill_color [0] * 255 + 0.5), floor (info.fill_color [1] * 255 + 0.5), floor (info.fill_color [2] * 255 + 0.5), floor (info.fill_color [3] * 255 + 0.5)));
+
+  QColor fc (floor (info.frame_color [0] * 255 + 0.5), floor (info.frame_color [1] * 255 + 0.5), floor (info.frame_color [2] * 255 + 0.5), floor (info.frame_color [3] * 255 + 0.5));
+  if (fc.alpha () > 0) {
+    QRgb fc_rgb = fc.rgba ();
+    for (int x = 0; x < icon_size.width (); ++x) {
+      img.setPixel (x, 0, fc_rgb);
+      img.setPixel (x, icon_size.height () - 1, fc_rgb);
+    }
+    for (int y = 0; y < icon_size.height (); ++y) {
+      img.setPixel (0, y, fc_rgb);
+      img.setPixel (icon_size.width () - 1, y, fc_rgb);
+    }
+  }
+
+  QIcon icon;
+  icon.addPixmap (QPixmap::fromImage (img));
+  item->setIcon (icon);
+}
+
+void
+D25View::finish ()
+{
+  if (! mp_ui->d25_view->has_error ()) {
+
+    mp_ui->d25_view->finish ();
+
+    QFontMetrics fm (mp_ui->material_list->font ());
+    QSize icon_size = fm.size (Qt::TextSingleLine, "WW");
+    icon_size.setHeight (icon_size.height () - 2);
+    mp_ui->material_list->setIconSize (icon_size);
+
+    mp_ui->material_list->clear ();
+    const std::vector<lay::D25ViewWidget::LayerInfo> &layers = mp_ui->d25_view->layers ();
+    for (auto l = layers.begin (); l != layers.end (); ++l) {
+      QListWidgetItem *item = new QListWidgetItem (mp_ui->material_list);
+      item->setFlags (item->flags () | Qt::ItemIsUserCheckable);
+      item->setCheckState (Qt::Checked);
+      layer_info_to_item (*l, item, l - layers.begin (), icon_size);
+    }
+
+    mp_ui->d25_view->reset ();
+    mp_ui->d25_view->set_cam_azimuth (0.0);
+    mp_ui->d25_view->set_cam_elevation (-initial_elevation);
+    //  NOTE: needs to be delayed to allow the geometry to be updated before (initial call)
+    dm_fit ();
+
+    mp_ui->rerun_button->setEnabled (true);
+    mp_ui->gl_stack->setCurrentIndex (0);
+
+  }
+}
+
+void
+D25View::fit ()
+{
+  mp_ui->d25_view->fit ();
+}
+
 static QString scale_factor_to_string (double f)
 {
   return QString (QString::fromUtf8 ("%1")).arg (f, 0, 'g', 3);
@@ -123,6 +313,7 @@ D25View::init_failed ()
 {
   mp_ui->error_text->setPlainText (tl::to_qstring (mp_ui->d25_view->error ()));
   mp_ui->gl_stack->setCurrentIndex (1);
+  mp_ui->rerun_button->setEnabled (false);
 }
 
 void
@@ -189,6 +380,15 @@ D25View::vscale_factor_changed (double f)
   mp_ui->vzoom_slider->blockSignals (false);
 }
 
+void
+D25View::material_item_changed (QListWidgetItem *item)
+{
+  int index = mp_ui->material_list->row (item);
+  if (index >= 0) {
+    mp_ui->d25_view->set_material_visible (size_t (index), item->checkState () == Qt::Checked);
+  }
+}
+
 void
 D25View::deactivated ()
 {
@@ -198,18 +398,33 @@ D25View::deactivated ()
 void
 D25View::activated ()
 {
-  bool any = mp_ui->d25_view->attach_view (view ());
-  if (! any) {
-    mp_ui->d25_view->attach_view (0);
-    throw tl::Exception (tl::to_string (tr ("No z data configured for the layers in this view.\nUse \"Tools/Manage Technologies\" to set up a z stack or check if it applies to the layers here.")));
-  }
-
+  mp_ui->d25_view->attach_view (view ());
   mp_ui->d25_view->reset ();
   mp_ui->d25_view->set_cam_azimuth (0.0);
   mp_ui->d25_view->set_cam_elevation (-initial_elevation);
   mp_ui->d25_view->fit ();
 }
 
+void
+D25View::rerun_button_pressed ()
+{
+  //  NOTE: we use deferred execution, because otherwise the button won't get repainted properly
+  dm_rerun_macro ();
+}
+
+void
+D25View::rerun_macro ()
+{
+BEGIN_PROTECTED
+
+  if (! m_generator.empty ()) {
+    std::map<std::string, tl::Variant> add_pars;
+    tl::Recipe::make (m_generator, add_pars);
+  }
+
+END_PROTECTED
+}
+
 void
 D25View::fit_button_clicked ()
 {
@@ -242,6 +457,42 @@ D25View::fit_button_clicked ()
   mp_ui->d25_view->fit ();
 }
 
+void
+D25View::hide_all_triggered ()
+{
+  for (int i = 0; i < mp_ui->material_list->count (); ++i) {
+    mp_ui->material_list->item (i)->setCheckState (Qt::Unchecked);
+  }
+}
+
+void
+D25View::hide_selected_triggered ()
+{
+  for (int i = 0; i < mp_ui->material_list->count (); ++i) {
+    if (mp_ui->material_list->item (i)->isSelected ()) {
+      mp_ui->material_list->item (i)->setCheckState (Qt::Unchecked);
+    }
+  }
+}
+
+void
+D25View::show_all_triggered ()
+{
+  for (int i = 0; i < mp_ui->material_list->count (); ++i) {
+    mp_ui->material_list->item (i)->setCheckState (Qt::Checked);
+  }
+}
+
+void
+D25View::show_selected_triggered ()
+{
+  for (int i = 0; i < mp_ui->material_list->count (); ++i) {
+    if (mp_ui->material_list->item (i)->isSelected ()) {
+      mp_ui->material_list->item (i)->setCheckState (Qt::Checked);
+    }
+  }
+}
+
 void 
 D25View::accept ()
 {
diff --git a/src/plugins/tools/view_25d/lay_plugin/layD25View.h b/src/plugins/tools/view_25d/lay_plugin/layD25View.h
index a4e420576..724c14e25 100644
--- a/src/plugins/tools/view_25d/lay_plugin/layD25View.h
+++ b/src/plugins/tools/view_25d/lay_plugin/layD25View.h
@@ -24,9 +24,11 @@
 #define HDR_layD25View
 
 #include <QDialog>
+#include <QListWidgetItem>
 
 #include "tlObject.h"
 #include "layBrowser.h"
+#include "layViewOp.h"
 
 namespace Ui
 {
@@ -38,6 +40,14 @@ namespace lay
   class LayoutView;
 }
 
+namespace db
+{
+  class Region;
+  class Edges;
+  class EdgePairs;
+  struct LayerProperties;
+}
+
 namespace lay
 {
 
@@ -54,6 +64,17 @@ public:
   virtual void deactivated ();
   virtual void activated ();
 
+  static D25View *open (lay::LayoutView *view);
+  void close ();
+  void clear ();
+  void begin (const std::string &generator);
+  void open_display (const color_t *frame_color, const color_t *fill_color, const db::LayerProperties *like, const std::string *name);
+  void close_display ();
+  void entry (const db::Region &data, double dbu, double zstart, double zstop);
+  void entry_edge (const db::Edges &data, double dbu, double zstart, double zstop);
+  void entry_edge_pair (const db::EdgePairs &data, double dbu, double zstart, double zstop);
+  void finish ();
+
 protected:
   void accept ();
   void reject ();
@@ -67,12 +88,23 @@ private slots:
   void vscale_slider_changed (int value);
   void vscale_value_edited ();
   void init_failed ();
+  void rerun_button_pressed ();
+  void material_item_changed (QListWidgetItem *);
+  void hide_all_triggered ();
+  void hide_selected_triggered ();
+  void show_all_triggered ();
+  void show_selected_triggered ();
 
 private:
   Ui::D25View *mp_ui;
+  tl::DeferredMethod<D25View> dm_rerun_macro;
+  tl::DeferredMethod<D25View> dm_fit;
+  std::string m_generator;
 
   void cellviews_changed ();
   void layer_properties_changed (int);
+  void rerun_macro ();
+  void fit ();
 };
 
 }
diff --git a/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.cc b/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.cc
index 57812aeb6..94e7f2705 100644
--- a/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.cc
+++ b/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.cc
@@ -26,11 +26,16 @@
 #include "layLayoutView.h"
 
 #include "dbRecursiveShapeIterator.h"
-#include "dbD25TechnologyComponent.h"
 #include "dbEdgeProcessor.h"
 #include "dbPolygonGenerators.h"
 #include "dbPolygonTools.h"
 #include "dbClip.h"
+#include "dbRegion.h"
+#include "dbEdges.h"
+#include "dbEdgePairs.h"
+#include "dbOriginalLayerRegion.h"
+#include "dbOriginalLayerEdges.h"
+#include "dbOriginalLayerEdgePairs.h"
 
 #include "tlException.h"
 #include "tlProgress.h"
@@ -200,7 +205,10 @@ D25ViewWidget::D25ViewWidget (QWidget *parent)
   setFormat (format);
 
   m_zmin = m_zmax = 0.0;
+  m_zset = false;
+  m_display_open = false;
   mp_view = 0;
+  m_has_error = false;
 
   reset_viewport ();
 }
@@ -477,6 +485,15 @@ D25ViewWidget::refresh ()
   update ();
 }
 
+void
+D25ViewWidget::set_material_visible (size_t index, bool visible)
+{
+  if (index < m_layers.size () && m_layers [index].visible != visible) {
+    m_layers [index].visible = visible;
+    update ();
+  }
+}
+
 void
 D25ViewWidget::showEvent (QShowEvent *)
 {
@@ -496,86 +513,22 @@ D25ViewWidget::aspect_ratio () const
   return double (width ()) / double (height ());
 }
 
-bool
-D25ViewWidget::attach_view (LayoutView *view)
+void
+D25ViewWidget::clear ()
 {
-  mp_view = view;
+  m_layers.clear ();
+  m_vertex_chunks.clear ();
+  m_line_chunks.clear ();
 
-  bool any = prepare_view ();
-  reset ();
-
-  return any;
-}
-
-namespace {
-
-  class ZDataCache
-  {
-  public:
-    ZDataCache () { }
-
-    std::vector<db::D25LayerInfo> operator() (lay::LayoutView *view, int cv_index, int layer_index)
-    {
-      std::map<int, std::map<int, std::vector<db::D25LayerInfo> > >::const_iterator c = m_cache.find (cv_index);
-      if (c != m_cache.end ()) {
-        std::map<int, std::vector<db::D25LayerInfo> >::const_iterator l = c->second.find (layer_index);
-        if (l != c->second.end ()) {
-          return l->second;
-        } else {
-          return std::vector<db::D25LayerInfo> ();
-        }
-      }
-
-      std::map<int, std::vector<db::D25LayerInfo> > &lcache = m_cache [cv_index];
-
-      const db::D25TechnologyComponent *comp = 0;
-
-      const lay::CellView &cv = view->cellview (cv_index);
-      if (cv.is_valid () && cv->technology ()) {
-        const db::Technology *tech = cv->technology ();
-        comp = dynamic_cast<const db::D25TechnologyComponent *> (tech->component_by_name ("d25"));
-      }
-
-      if (comp) {
-
-        std::multimap<db::LayerProperties, db::D25LayerInfo, db::LPLogicalLessFunc> zi_by_lp;
-
-        db::D25TechnologyComponent::layers_type layers = comp->compile_from_source ();
-        for (db::D25TechnologyComponent::layers_type::const_iterator i = layers.begin (); i != layers.end (); ++i) {
-          zi_by_lp.insert (std::make_pair (i->layer (), *i));
-        }
-
-        const db::Layout &ly = cv->layout ();
-        for (int l = 0; l < int (ly.layers ()); ++l) {
-          if (ly.is_valid_layer (l)) {
-            db::LayerProperties lp = ly.get_properties (l);
-            std::multimap<db::LayerProperties, db::D25LayerInfo, db::LPLogicalLessFunc>::const_iterator z = zi_by_lp.find (lp);
-            if ((z == zi_by_lp.end () || ! z->first.log_equal (lp)) && ! lp.name.empty ()) {
-              //  If possible, try by name only
-              lp = db::LayerProperties (lp.name);
-              z = zi_by_lp.find (lp);
-            }
-            while (z != zi_by_lp.end () && z->first.log_equal (lp)) {
-              lcache[l].push_back (z->second);
-              ++z;
-            }
-          }
-        }
-
-      }
-
-      std::map<int, std::vector<db::D25LayerInfo> >::const_iterator l = lcache.find (layer_index);
-      if (l != lcache.end ()) {
-        return l->second;
-      } else {
-        return std::vector<db::D25LayerInfo> ();
-      }
-    }
-
-  private:
-    std::map<int, std::map<int, std::vector<db::D25LayerInfo> > > m_cache;
-  };
+  m_zset = false;
+  m_zmin = m_zmax = 0.0;
+  m_display_open = false;
 
+  if (! mp_view) {
+    m_bbox = db::DBox (-1.0, -1.0, 1.0, 1.0);
+  } else {
+    m_bbox = mp_view->viewport ().box ();
+  }
 }
 
 static void color_to_gl (color_t color, GLfloat (&gl_color) [4])
@@ -586,130 +539,181 @@ static void color_to_gl (color_t color, GLfloat (&gl_color) [4])
   gl_color[3] = 1.0f;
 }
 
-void
-D25ViewWidget::lp_to_info (const lay::LayerPropertiesNode &lp, LayerInfo &info)
+static void color_to_gl (const color_t *color, GLfloat (&gl_color) [4])
 {
-  color_to_gl (lp.fill_color (true), info.color);
+  if (! color) {
+    for (unsigned int i = 0; i < 4; ++i) {
+      gl_color [i] = 0.0;
+    }
+  } else {
+    color_to_gl (*color, gl_color);
+  }
+}
+
+static void lp_to_info (const lay::LayerPropertiesNode &lp, D25ViewWidget::LayerInfo &info)
+{
+  color_to_gl (lp.fill_color (true), info.fill_color);
   if (lp.dither_pattern (true) == 1 /*hollow*/) {
-    info.color [3] = 0.0f;
+    info.fill_color [3] = 0.0f;
   }
 
   color_to_gl (lp.frame_color (true), info.frame_color);
-  if (lp.frame_color (true) == lp.fill_color (true) && info.color [3] > 0.5) {
+  if (lp.frame_color (true) == lp.fill_color (true) && info.fill_color [3] > 0.5) {
     //  optimize: don't draw wire frame unless required
     info.frame_color [3] = 0.0f;
   }
 
-  info.visible = lp.visible (true);
-}
-
-bool
-D25ViewWidget::prepare_view ()
-{
-  m_layers.clear ();
-  m_layer_to_info.clear ();
-  m_vertex_chunks.clear ();
-  m_line_chunks.clear ();
-
-  bool zset = false;
-  m_zmin = m_zmax = 0.0;
-
-  if (! mp_view) {
-    m_bbox = db::DBox (-1.0, -1.0, 1.0, 1.0);
-    return false;
-  }
-
-  m_bbox = mp_view->viewport ().box ();
-
-  ZDataCache zdata;
-
-  //  collect and confine to cell bbox
-  db::DBox cell_bbox;
-  for (lay::LayerPropertiesConstIterator lp = mp_view->begin_layers (); ! lp.at_end (); ++lp) {
-
-    std::vector<db::D25LayerInfo> zinfo;
-    if (! lp->has_children ()) {
-      zinfo = zdata (mp_view, lp->cellview_index (), lp->layer_index ());
-    }
-
-    for (std::vector<db::D25LayerInfo>::const_iterator zi = zinfo.begin (); zi != zinfo.end (); ++zi) {
-      const lay::CellView &cv = mp_view->cellview ((unsigned int) lp->cellview_index ());
-      cell_bbox += db::CplxTrans (cv->layout ().dbu ()) * cv.cell ()->bbox ((unsigned int) lp->layer_index ());
-    }
-
-  }
-
-  bool any = false;
-
-  tl::AbsoluteProgress progress (tl::to_string (tr ("Rendering ...")));
-
-  for (lay::LayerPropertiesConstIterator lp = mp_view->begin_layers (); ! lp.at_end (); ++lp) {
-
-    std::vector<db::D25LayerInfo> zinfo;
-    if (! lp->has_children ()) {
-      zinfo = zdata (mp_view, lp->cellview_index (), lp->layer_index ());
-    }
-
-    for (std::vector<db::D25LayerInfo>::const_iterator zi = zinfo.begin (); zi != zinfo.end (); ++zi) {
-
-      any = true;
-
-      double z0 = zi->zstart ();
-      double z1 = zi->zstop ();
-
-      m_vertex_chunks.push_back (triangle_chunks_type ());
-      m_line_chunks.push_back (line_chunks_type ());
-
-      LayerInfo info;
-      lp_to_info (*lp, info);
-      info.vertex_chunk = &m_vertex_chunks.back ();
-      info.line_chunk = &m_line_chunks.back ();
-
-      m_layer_to_info.insert (std::make_pair (std::make_pair (lp->cellview_index (), lp->layer_index ()), m_layers.size ()));
-      m_layers.push_back (info);
-
-      const lay::CellView &cv = mp_view->cellview ((unsigned int) lp->cellview_index ());
-
-      render_layout (progress, m_vertex_chunks.back (), m_line_chunks.back (), cv->layout (), *cv.cell (), db::CplxTrans (cv->layout ().dbu ()).inverted () * m_bbox, (unsigned int) lp->layer_index (), z0, z1);
-
-      if (! zset) {
-        m_zmin = z0;
-        m_zmax = z1;
-        zset = true;
-      } else {
-        m_zmin = std::min (z0, m_zmin);
-        m_zmax = std::max (z1, m_zmax);
-      }
-
-    }
-
-  }
-
-  return any;
+  info.visible = true;
 }
 
 void
-D25ViewWidget::refresh_view ()
+D25ViewWidget::open_display (const color_t *frame_color, const color_t *fill_color, const db::LayerProperties *like, const std::string *name)
 {
-  if (! mp_view) {
-    return;
+  m_vertex_chunks.push_back (triangle_chunks_type ());
+  m_line_chunks.push_back (line_chunks_type ());
+
+  LayerInfo info;
+
+  info.visible = true;
+  color_to_gl (frame_color, info.frame_color);
+  color_to_gl (fill_color, info.fill_color);
+
+  info.has_name = (name != 0 || like != 0);
+  if (name) {
+    info.name = *name;
+  } else if (like) {
+    info.name = like->to_string ();
   }
 
-  for (lay::LayerPropertiesConstIterator lp = mp_view->begin_layers (); ! lp.at_end (); ++lp) {
+  info.vertex_chunk = &m_vertex_chunks.back ();
+  info.line_chunk = &m_line_chunks.back ();
 
-    std::pair<size_t, size_t> key = std::make_pair (lp->cellview_index (), lp->layer_index ());
-
-    std::multimap<std::pair<size_t, size_t>, size_t>::const_iterator l = m_layer_to_info.find (key);
-    while (l != m_layer_to_info.end () && l->first == key) {
-      if (l->second < m_layers.size ()) {
-        lp_to_info (*lp, m_layers [l->second]);
+  if (like && mp_view) {
+    for (lay::LayerPropertiesConstIterator lp = mp_view->begin_layers (); ! lp.at_end (); ++lp) {
+      if (! lp->has_children () && lp->source (true).layer_props ().log_equal (*like)) {
+        lp_to_info (*lp, info);
+        break;
       }
-      ++l;
+    }
+  }
+
+  m_layers.push_back (info);
+  m_display_open = true;
+}
+
+void
+D25ViewWidget::close_display ()
+{
+  m_display_open = false;
+}
+
+void
+D25ViewWidget::enter (const db::RecursiveShapeIterator *iter, double zstart, double zstop)
+{
+  tl_assert (m_display_open);
+
+  if (! m_zset) {
+    m_zmin = std::min (zstart, zstop);
+    m_zmax = std::max (zstart, zstop);
+    m_zset = true;
+  } else {
+    m_zmin = std::min (m_zmin, std::min (zstart, zstop));
+    m_zmax = std::min (m_zmax, std::max (zstart, zstop));
+  }
+
+  LayerInfo &info = m_layers.back ();
+
+  //  try to establish a default color from the region's origin if required
+  if (mp_view && info.fill_color [3] == 0.0 && info.frame_color [3] == 0.0) {
+
+    if (iter) {
+
+      if (iter && iter->layout () && iter->layout ()->is_valid_layer (iter->layer ())) {
+
+        db::LayerProperties like = iter->layout ()->get_properties (iter->layer ());
+
+        for (lay::LayerPropertiesConstIterator lp = mp_view->begin_layers (); ! lp.at_end (); ++lp) {
+          if (! lp->has_children () && lp->source (true).layer_props ().log_equal (like)) {
+            lp_to_info (*lp, info);
+            if (! info.has_name) {
+              info.name = like.to_string ();
+              info.has_name = true;
+            }
+            break;
+          }
+        }
+
+      }
+
+    } else {
+
+      //  sequential assignment
+      lay::color_t color = mp_view->get_palette ().luminous_color_by_index (m_layers.size ());
+      color_to_gl (color, info.fill_color);
+
     }
 
   }
+}
 
-  refresh ();
+void
+D25ViewWidget::entry (const db::Region &data, double dbu, double zstart, double zstop)
+{
+  //  try to establish a default color from the region's origin if required
+  const db::RecursiveShapeIterator *iter = 0;
+  const db::OriginalLayerRegion *original = dynamic_cast<db::OriginalLayerRegion *> (data.delegate ());
+  if (original) {
+    iter = original->iter ();
+  }
+
+  enter (iter, zstart, zstop);
+
+  tl::AbsoluteProgress progress (tl::to_string (tr ("Rendering ...")));
+  render_region (progress, *m_layers.back ().vertex_chunk, *m_layers.back ().line_chunk, data, dbu, db::CplxTrans (dbu).inverted () * m_bbox, zstart, zstop);
+}
+
+void
+D25ViewWidget::entry (const db::Edges &data, double dbu, double zstart, double zstop)
+{
+  //  try to establish a default color from the region's origin if required
+  const db::RecursiveShapeIterator *iter = 0;
+  const db::OriginalLayerEdges *original = dynamic_cast<db::OriginalLayerEdges *> (data.delegate ());
+  if (original) {
+    iter = original->iter ();
+  }
+
+  enter (iter, zstart, zstop);
+
+  tl::AbsoluteProgress progress (tl::to_string (tr ("Rendering ...")));
+  render_edges (progress, *m_layers.back ().vertex_chunk, *m_layers.back ().line_chunk, data, dbu, db::CplxTrans (dbu).inverted () * m_bbox, zstart, zstop);
+}
+
+void
+D25ViewWidget::entry (const db::EdgePairs &data, double dbu, double zstart, double zstop)
+{
+  //  try to establish a default color from the region's origin if required
+  const db::RecursiveShapeIterator *iter = 0;
+  const db::OriginalLayerEdgePairs *original = dynamic_cast<db::OriginalLayerEdgePairs *> (data.delegate ());
+  if (original) {
+    iter = original->iter ();
+  }
+
+  enter (iter, zstart, zstop);
+
+  tl::AbsoluteProgress progress (tl::to_string (tr ("Rendering ...")));
+  render_edge_pairs (progress, *m_layers.back ().vertex_chunk, *m_layers.back ().line_chunk, data, dbu, db::CplxTrans (dbu).inverted () * m_bbox, zstart, zstop);
+}
+
+void
+D25ViewWidget::finish ()
+{
+  //  .. nothing yet ..
+}
+
+void
+D25ViewWidget::attach_view (LayoutView *view)
+{
+  mp_view = view;
 }
 
 void
@@ -793,31 +797,23 @@ D25ViewWidget::render_wall (D25ViewWidget::triangle_chunks_type &chunks, D25View
 }
 
 void
-D25ViewWidget::render_layout (tl::AbsoluteProgress &progress, D25ViewWidget::triangle_chunks_type &chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::Layout &layout, const db::Cell &cell, const db::Box &clip_box, unsigned int layer, double zstart, double zstop)
+D25ViewWidget::render_region (tl::AbsoluteProgress &progress, D25ViewWidget::triangle_chunks_type &chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::Region &region, double dbu, const db::Box &clip_box, double zstart, double zstop)
 {
   std::vector<db::Polygon> poly_heap;
 
-  //  TODO: hidden cells, hierarchy depth ...
-
-  db::RecursiveShapeIterator s (layout, cell, layer, clip_box);
-  s.shape_flags (db::ShapeIterator::Polygons | db::ShapeIterator::Paths | db::ShapeIterator::Boxes);
-  for ( ; ! s.at_end (); ++s) {
-
-    db::Polygon polygon;
-    s->polygon (polygon);
-    polygon.transform (s.trans ());
+  for (db::Region::const_iterator p = region.begin (); !p.at_end (); ++p) {
 
     poly_heap.clear ();
-    db::clip_poly (polygon, clip_box, poly_heap, false /*keep holes*/);
+    db::clip_poly (*p, clip_box, poly_heap, false /*keep holes*/);
 
     for (std::vector<db::Polygon>::const_iterator p = poly_heap.begin (); p != poly_heap.end (); ++p) {
 
       ++progress;
 
-      render_polygon (chunks, line_chunks, *p, layout.dbu (), zstart, zstop);
+      render_polygon (chunks, line_chunks, *p, dbu, zstart, zstop);
 
       for (db::Polygon::polygon_edge_iterator e = p->begin_edge (); ! e.at_end (); ++e) {
-        render_wall (chunks, line_chunks, *e, layout.dbu (), zstart, zstop);
+        render_wall (chunks, line_chunks, *e, dbu, zstart, zstop);
       }
 
     }
@@ -825,6 +821,43 @@ D25ViewWidget::render_layout (tl::AbsoluteProgress &progress, D25ViewWidget::tri
   }
 }
 
+void
+D25ViewWidget::render_edges (tl::AbsoluteProgress &progress, D25ViewWidget::triangle_chunks_type &chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::Edges &edges, double dbu, const db::Box &clip_box, double zstart, double zstop)
+{
+  for (db::Edges::const_iterator e = edges.begin (); !e.at_end (); ++e) {
+
+    ++progress;
+
+    std::pair<bool, db::Edge> ec = e->clipped (clip_box);
+    if (ec.first) {
+      render_wall (chunks, line_chunks, ec.second, dbu, zstart, zstop);
+    }
+
+  }
+}
+
+void
+D25ViewWidget::render_edge_pairs (tl::AbsoluteProgress &progress, D25ViewWidget::triangle_chunks_type &chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::EdgePairs &edge_pairs, double dbu, const db::Box &clip_box, double zstart, double zstop)
+{
+  for (db::EdgePairs::const_iterator e = edge_pairs.begin (); !e.at_end (); ++e) {
+
+    ++progress;
+
+    std::pair<bool, db::Edge> ec;
+
+    ec = e->first ().clipped (clip_box);
+    if (ec.first) {
+      render_wall (chunks, line_chunks, ec.second, dbu, zstart, zstop);
+    }
+
+    ec = e->second ().clipped (clip_box);
+    if (ec.first) {
+      render_wall (chunks, line_chunks, ec.second, dbu, zstart, zstop);
+    }
+
+  }
+}
+
 static std::pair<double, double> find_grid (double v)
 {
   for (int p = -12; p < 12; ++p) {
@@ -852,22 +885,22 @@ D25ViewWidget::initializeGL ()
   tl_assert (m_gridplane_program == 0);
   tl_assert (m_lines_program == 0);
 
-  bool error = false;
+  m_has_error = false;
 
   try {
     do_initialize_gl ();
   } catch (tl::Exception &ex) {
     m_error = ex.msg ();
-    error = true;
+    m_has_error = true;
   } catch (std::exception &ex) {
     m_error = ex.what ();
-    error = true;
+    m_has_error = true;
   } catch (...) {
     m_error = "(unspecific error)";
-    error = true;
+    m_has_error = true;
   }
 
-  if (error) {
+  if (m_has_error) {
 
     delete m_shapes_program;
     m_shapes_program = 0;
@@ -1098,8 +1131,8 @@ D25ViewWidget::paintGL ()
   glEnableVertexAttribArray (positions);
 
   for (std::vector<LayerInfo>::const_iterator l = m_layers.begin (); l != m_layers.end (); ++l) {
-    if (l->visible && l->color [3] > 0.5) {
-      m_shapes_program->setUniformValue ("color", l->color [0], l->color [1], l->color [2], l->color [3]);
+    if (l->visible && l->fill_color [3] > 0.5) {
+      m_shapes_program->setUniformValue ("color", l->fill_color [0], l->fill_color [1], l->fill_color [2], l->fill_color [3]);
       l->vertex_chunk->draw_to (this, positions, GL_TRIANGLES);
     }
   }
diff --git a/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.h b/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.h
index 63b069463..af5dd0a54 100644
--- a/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.h
+++ b/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.h
@@ -27,6 +27,7 @@
 
 #include "layD25MemChunks.h"
 #include "layD25Camera.h"
+#include "layViewOp.h"
 
 #include <QOpenGLWidget>
 #include <QOpenGLVertexArrayObject>
@@ -41,8 +42,11 @@
 
 namespace db
 {
-  class Layout;
-  class Cell;
+  class Region;
+  class Edges;
+  class EdgePairs;
+  class RecursiveShapeIterator;
+  struct LayerProperties;
 }
 
 namespace tl
@@ -78,6 +82,20 @@ class D25ViewWidget
 Q_OBJECT 
 
 public:
+  typedef lay::mem_chunks<GLfloat, 1024 * 18> triangle_chunks_type;
+  typedef lay::mem_chunks<GLfloat, 1024 * 6> line_chunks_type;
+
+  struct LayerInfo
+  {
+    triangle_chunks_type *vertex_chunk;
+    line_chunks_type *line_chunk;
+    GLfloat fill_color [4];
+    GLfloat frame_color [4];
+    bool visible;
+    std::string name;
+    bool has_name;
+  };
+
   D25ViewWidget (QWidget *parent);
   ~D25ViewWidget ();
 
@@ -88,8 +106,7 @@ public:
   void mouseReleaseEvent (QMouseEvent *event);
   void mouseMoveEvent (QMouseEvent *event);
 
-  bool attach_view(lay::LayoutView *view);
-  void refresh_view ();
+  void attach_view(lay::LayoutView *view);
 
   QVector3D hit_point_with_scene(const QVector3D &line_dir);
   void refresh ();
@@ -129,6 +146,26 @@ public:
     return m_error;
   }
 
+  bool has_error () const
+  {
+    return m_has_error;
+  }
+
+  const std::vector<LayerInfo> &layers () const
+  {
+    return m_layers;
+  }
+
+  void set_material_visible (size_t index, bool visible);
+
+  void clear ();
+  void open_display (const color_t *frame_color, const color_t *fill_color, const db::LayerProperties *like, const std::string *name);
+  void close_display ();
+  void entry (const db::Region &data, double dbu, double zstart, double zstop);
+  void entry (const db::Edges &data, double dbu, double zstart, double zstop);
+  void entry (const db::EdgePairs &data, double dbu, double zstart, double zstop);
+  void finish ();
+
 signals:
   void scale_factor_changed (double f);
   void vscale_factor_changed (double f);
@@ -143,44 +180,36 @@ public slots:
   void fit ();
 
 private:
-  typedef lay::mem_chunks<GLfloat, 1024 * 18> triangle_chunks_type;
-  typedef lay::mem_chunks<GLfloat, 1024 * 6> line_chunks_type;
-
   std::unique_ptr<D25InteractionMode> mp_mode;
   QOpenGLShaderProgram *m_shapes_program, *m_lines_program, *m_gridplane_program;
   std::string m_error;
+  bool m_has_error;
   double m_scale_factor;
   double m_vscale_factor;
   QVector3D m_displacement;
   lay::LayoutView *mp_view;
   db::DBox m_bbox;
   double m_zmin, m_zmax;
+  bool m_zset;
+  bool m_display_open;
 
   std::list<triangle_chunks_type> m_vertex_chunks;
   std::list<line_chunks_type> m_line_chunks;
 
-  struct LayerInfo {
-    const triangle_chunks_type *vertex_chunk;
-    const line_chunks_type *line_chunk;
-    GLfloat color [4];
-    GLfloat frame_color [4];
-    bool visible;
-  };
-
   std::vector<LayerInfo> m_layers;
-  std::multimap<std::pair<size_t, size_t>, size_t> m_layer_to_info;
 
   void initializeGL ();
   void paintGL ();
   void resizeGL (int w, int h);
 
   void do_initialize_gl ();
-  bool prepare_view();
-  void render_layout (tl::AbsoluteProgress &progress, D25ViewWidget::triangle_chunks_type &vertex_chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::Layout &layout, const db::Cell &cell, const db::Box &clip_box, unsigned int layer, double zstart, double zstop);
+  void render_region (tl::AbsoluteProgress &progress, D25ViewWidget::triangle_chunks_type &vertex_chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::Region &region, double dbu, const db::Box &clip_box, double zstart, double zstop);
+  void render_edges (tl::AbsoluteProgress &progress, D25ViewWidget::triangle_chunks_type &vertex_chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::Edges &region, double dbu, const db::Box &clip_box, double zstart, double zstop);
+  void render_edge_pairs (tl::AbsoluteProgress &progress, D25ViewWidget::triangle_chunks_type &vertex_chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::EdgePairs &region, double dbu, const db::Box &clip_box, double zstart, double zstop);
   void render_polygon (D25ViewWidget::triangle_chunks_type &vertex_chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::Polygon &poly, double dbu, double zstart, double zstop);
   void render_wall (D25ViewWidget::triangle_chunks_type &vertex_chunks, D25ViewWidget::line_chunks_type &line_chunks, const db::Edge &poly, double dbu, double zstart, double zstop);
   void reset_viewport ();
-  static void lp_to_info (const lay::LayerPropertiesNode &lp, D25ViewWidget::LayerInfo &info);
+  void enter (const db::RecursiveShapeIterator *iter, double zstart, double zstop);
 };
 
 }
diff --git a/src/plugins/tools/view_25d/lay_plugin/lay_plugin.pro b/src/plugins/tools/view_25d/lay_plugin/lay_plugin.pro
index b05f93e94..220aa3cf8 100644
--- a/src/plugins/tools/view_25d/lay_plugin/lay_plugin.pro
+++ b/src/plugins/tools/view_25d/lay_plugin/lay_plugin.pro
@@ -4,9 +4,13 @@ DESTDIR = $$OUT_PWD/../../../../lay_plugins
 
 include($$PWD/../../../lay_plugin.pri)
 
-INCLUDEPATH += $$RDB_INC $$ANT_INC
-DEPENDPATH += $$RDB_INC $$ANT_INC
+INCLUDEPATH += $$RDB_INC $$ANT_INC $$QTBASIC_INC
+DEPENDPATH += $$RDB_INC $$ANT_INC $$QTBASIC_INC
+
 LIBS += -L$$DESTDIR/.. -lklayout_rdb -lklayout_ant
+equals(HAVE_QTBINDINGS, "1") {
+  LIBS += -lklayout_qtbasic -lklayout_QtGui -lklayout_QtCore
+}
 
 HEADERS = \
   layD25View.h \
@@ -16,6 +20,7 @@ HEADERS = \
     layD25Camera.h
 
 SOURCES = \
+  gsiDeclLayD25View.cc \
   layD25View.cc \
   layD25ViewWidget.cc \
   layD25Plugin.cc \
@@ -26,6 +31,9 @@ SOURCES = \
 FORMS = \
   D25View.ui \
 
+RESOURCES = \
+  layD25Resources.qrc \
+
 greaterThan(QT_MAJOR_VERSION, 5) {
   QT += openglwidgets
 }
diff --git a/src/plugins/tools/view_25d/lay_plugin/templates/d25.lym b/src/plugins/tools/view_25d/lay_plugin/templates/d25.lym
new file mode 100644
index 000000000..7580c81c6
--- /dev/null
+++ b/src/plugins/tools/view_25d/lay_plugin/templates/d25.lym
@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="utf-8"?>
+<klayout-macro>
+ <description>General;;2.5d view generator script (*.lyd25)\nA script generating a 2.5d view</description>
+ <version/>
+ <category>d25</category>
+ <prolog/>
+ <epilog/>
+ <doc/>
+ <autorun>false</autorun>
+ <autorun-early>false</autorun-early>
+ <shortcut/>
+ <show-in-menu>true</show-in-menu>
+ <group-name>d25_scripts</group-name>
+ <menu-path>tools_menu.d25.end</menu-path>
+ <interpreter>ruby</interpreter>
+ <dsl-interpreter-name/>
+ <text>
+# Read about 2.5d generator scripts in the User Manual in "Various Topics/The 2.5d View"
+
+# The script utilizes the DRC language with these two extensions
+# 
+# z(layer, options ...):
+#
+#   This function generates a extruded view from the given layer.
+#   
+#   Some options control the z extrusion:
+#
+#     z(layer, 0.1 .. 0.2)                extrude layer to z = 0.1 to 0.2 um
+#     z(layer, zstart: 0.1, zstop: 0.2)   same as above
+#     z(layer, zstart: 0.1, height: 0.1)  same as above, but with height instead of zstop
+#     z(layer, height: 200.nm)            extrude layer from last z position with a height of 200nm
+#
+#   You can specify display options:
+#
+#     z(..., color: 0xff0000)             use bright red for the material color (RGB)
+#     z(..., frame: 0xff0000)             use bright red for the frame color (combine with "fill" for the fill color)
+#     z(..., fill: 0x00ff00)              use bright green for the fill color along (combine with "frame" for the frame color)
+#     z(..., like: "7/0")                 borrow style from layout view's style for layer "7/0"
+#     z(..., name: "M1")                  assigns a name to show for the material 
+#   
+#   If no display options are given and layer is an original layer, the colors are taken
+#   from the original layer's display style. Otherwise KLayout decides about the 
+#   colors itself using the application's palette. 
+#
+# zz(options) { block }
+# zz(z(...), z(...), ..., options):
+#
+#   Creates a display group. The display options are the same for all
+#   extrusion specs within the group. 
+#
+#   The options of "zz" are "name", "color", "frame", "fill" and "like".
+
+z(input(1, 0), 0.1 .. 0.2)
+z(input(2, 0), height: 250.nm, color: 0xffbc80)
+
+zz(like: 7/0, name: "Metal") do
+  z(input(7, 0), height: 100.nm)
+  z(input(8, 0), height: 150.nm)
+end
+
+</text>
+</klayout-macro>
+
diff --git a/testdata/algo/layout_utils_au_sns4.oas b/testdata/algo/layout_utils_au_sns4.oas
new file mode 100644
index 000000000..3213ccba4
Binary files /dev/null and b/testdata/algo/layout_utils_au_sns4.oas differ
diff --git a/testdata/algo/scale_and_snap4.oas b/testdata/algo/scale_and_snap4.oas
new file mode 100644
index 000000000..a92021ed5
Binary files /dev/null and b/testdata/algo/scale_and_snap4.oas differ