diff --git a/config.cpp b/config.cpp
index 96ca6614..3c6ea72e 100644
--- a/config.cpp
+++ b/config.cpp
@@ -1179,6 +1179,31 @@ void config_camera_rotation() {
     );
   }
 
+void add_edit_wall_quality(char c) {
+  dialog::addSelItem(XLAT("wall quality"), its(vid.texture_step), c);
+  dialog::add_action([] {
+    dialog::editNumber(vid.texture_step, 1, 16, 1, 1, XLAT("wall quality"), 
+      XLAT(
+      "Controls the number of triangles used for wall surfaces. "
+      "Higher numbers reduce the performance. "
+      "This has a strong effect when the walls are curved indeed "
+      "(honeycombs based on horospheres, and projections other than native perspective), "
+      "but otherwise, usually it can be set to 1 without significant adverse effects other "
+      "than slightly incorrect texturing."
+      )
+      );
+    dialog::bound_low(1);
+    dialog::bound_up(128);
+    dialog::reaction = [] {
+      if(floor_textures) {
+        delete floor_textures;
+        floor_textures = NULL;
+        }
+      need_reset_geometry = true;          
+      };
+    });
+  }
+
 void show3D() {
   cmode = sm::SIDE | sm::MAYDARK;
   gamescreen(0);
@@ -1245,30 +1270,7 @@ void show3D() {
       dialog::editNumber(vid.radarsize, 0, 360, 15, 90, "", "set to 0 to disable");
       });
     }
-  if(DIM == 3) {
-    dialog::addSelItem(XLAT("wall quality"), its(vid.texture_step), 'W');
-    dialog::add_action([] {
-      dialog::editNumber(vid.texture_step, 1, 16, 1, 1, XLAT("wall quality"), 
-        XLAT(
-        "Controls the number of triangles used for wall surfaces. "
-        "Higher numbers reduce the performance. "
-        "This has a strong effect when the walls are curved indeed "
-        "(honeycombs based on horospheres, and projections other than native perspective), "
-        "but otherwise, usually it can be set to 1 without significant adverse effects other "
-        "than slightly incorrect texturing."
-        )
-        );
-      dialog::bound_low(1);
-      dialog::bound_up(128);
-      dialog::reaction = [] {
-        if(floor_textures) {
-          delete floor_textures;
-          floor_textures = NULL;
-          }
-        need_reset_geometry = true;          
-        };
-      });
-    }
+  if(DIM == 3) add_edit_wall_quality('W');
   #endif
   
   dialog::addBreak(50);
diff --git a/floorshapes.cpp b/floorshapes.cpp
index 6b0a12a7..de1e33fc 100644
--- a/floorshapes.cpp
+++ b/floorshapes.cpp
@@ -464,6 +464,7 @@ void generate_floorshapes_for(int id, cell *c, int siid, int sidir) {
       }
     }
   
+  #if MAXMDIM >= 4
   if(WDIM == 2 && GDIM == 3) {
     finishshape();
     for(auto pfsh: all_plain_floorshapes) {
@@ -499,6 +500,12 @@ void generate_floorshapes_for(int id, cell *c, int siid, int sidir) {
             }
           }
         }
+
+      for(int l=0; l<SIDEPARS; l++) {
+        for(auto& li: fsh.side[l]) li.tinf = &fsh.tinf3;
+        for(int e=0; e<MAX_EDGE; e++)
+          for(auto& li: fsh.gpside[l][e]) li.tinf = &fsh.tinf3;
+        }
       }
       
     for(auto pfsh: all_escher_floorshapes) {
@@ -506,17 +513,18 @@ void generate_floorshapes_for(int id, cell *c, int siid, int sidir) {
       
       for(int l=0; l<SIDEPARS; l++) {
         fsh.levels[l] = shFullFloor.levels[l];
+        for(auto& li: fsh.levels[l]) li.tinf = &fsh.tinf3;
         fsh.side[l] = shFullFloor.side[l];
-        for(int e=0; e<MAX_EDGE; e++)
+        for(auto& li: fsh.side[l]) li.tinf = &fsh.tinf3;
+        for(int e=0; e<MAX_EDGE; e++) {
           fsh.gpside[l][e] = shFullFloor.gpside[l][e];
+          for(auto& li: fsh.gpside[l][e]) li.tinf = &fsh.tinf3;
+          }
         }
-      
-      for(auto& l: fsh.levels)
-      for(auto& li: l)
-        li.tinf = &fsh.tinf3;
       }
     finishshape();
     }
+  #endif
   }
 
 void generate_floorshapes() {
diff --git a/geom-exp.cpp b/geom-exp.cpp
index 8ec460ca..89f6ef81 100644
--- a/geom-exp.cpp
+++ b/geom-exp.cpp
@@ -631,6 +631,8 @@ void showEuclideanMenu() {
         #endif
         };
       });
+    extern void add_edit_wall_quality(char);
+    add_edit_wall_quality('W');
     }
   else if(WDIM == 3) dialog::addBreak(100);
   else {
diff --git a/polygons.cpp b/polygons.cpp
index 1aa67c7b..5dc4b40a 100644
--- a/polygons.cpp
+++ b/polygons.cpp
@@ -138,12 +138,33 @@ hyperpoint zshift(hyperpoint x, ld z) {
   }
 
 void chasmifyPoly(double fac, double fac2, int k) {
-  for(int i=isize(hpc)-1; i >= last->s; i--) {
-    hpc.push_back(zshift(hpc[i], fac));
-    hpc[i] = zshift(hpc[i], fac2);
+  if(GDIM == 2) {
+     for(int i=isize(hpc)-1; i >= last->s; i--) {
+       hpc.push_back(mscale(hpc[i], fac));
+       hpc[i] = mscale(hpc[i], fac2);
+       }
+     hpc.push_back(hpc[last->s]);
+     last->flags |= POLY_ISSIDE;
+     }
+  else {
+    vector<hyperpoint> points;
+    for(int s = last->s; s<isize(hpc); s++) points.push_back(hpc[s]);
+    hpc.resize(last->s);
+    last->flags |= POLY_TRIANGLES;
+    last->texture_offset = 0;
+    last->s = isize(hpc);
+    using namespace hyperpoint_vec;
+    auto at = [&] (ld x, ld y) {
+      x *= (isize(points) - 1);
+      int zf = int(x);
+      x -= zf;
+      hpcpush(zshift(points[zf] + (points[zf+1] - points[zf]) * x, fac + (fac2-fac) * y));
+      };
+    texture_order([&] (ld x, ld y) { at((1-x+y)/2, (1-x-y)/2); });
+    texture_order([&] (ld x, ld y) { at((1-x-y)/2, (1+x-y)/2); });
+    texture_order([&] (ld x, ld y) { at((1+x-y)/2, (1+x+y)/2); });
+    texture_order([&] (ld x, ld y) { at((1+x+y)/2, (1-x+y)/2); });      
     }
-  hpc.push_back(hpc[last->s]);
-  last->flags |= POLY_ISSIDE;
   }
 #endif