diff --git a/3d-models.cpp b/3d-models.cpp
index d64fb1c6..4f911df5 100644
--- a/3d-models.cpp
+++ b/3d-models.cpp
@@ -585,6 +585,7 @@ void geometry_information::make_revolution_cut(hpcshape &sh, int each, ld push,
     shDogStripes = shDogTorso;
     add_texture(shDogStripes);
     auto& utt = models_texture;
+    if(utt.tvertices.empty()) return;
     int a = (6 * 360 / step);
     for(int i=0; i<shDogStripes.e - shDogStripes.s; i++)
       if(i % (2 * a) < a)
@@ -770,7 +771,8 @@ void geometry_information::adjust_eye(hpcshape& eye, hpcshape head, ld shift_eye
     for(int i=eye.s; i<s; i++) {
       hpcpush(MirrorY * hpc[i]);
       auto& utt = models_texture;
-      utt.tvertices.push_back(utt.tvertices[i - eye.s + eye.texture_offset]);
+      if(!utt.tvertices.empty())
+        utt.tvertices.push_back(utt.tvertices[i - eye.s + eye.texture_offset]);
       }
 
   finishshape();
diff --git a/celldrawer.cpp b/celldrawer.cpp
index 3f33296d..a9b0fcd4 100644
--- a/celldrawer.cpp
+++ b/celldrawer.cpp
@@ -1618,7 +1618,7 @@ void celldrawer::draw_features_and_walls_3d() {
             poly.tinf = &texture::config.tinf3;
             poly.offset_texture = 0;
             }
-          else 
+          else if(!floor_texture_vertices.empty())
           #endif
           {
             poly.tinf = &floor_texture_vertices[qfi.fshape->id];
diff --git a/drawing.cpp b/drawing.cpp
index ff221bd8..b37089c2 100644
--- a/drawing.cpp
+++ b/drawing.cpp
@@ -407,6 +407,12 @@ void coords_to_poly() {
     }
   }
 
+bool behind3(hyperpoint h) {
+  if(pmodel == mdGeodesic)
+    h = lp_apply(inverse_exp(h, iTable));
+  return h[2] < 0;
+  }
+
 void addpoly(const transmatrix& V, const vector<glvertex> &tab, int ofs, int cnt) {
   if(pmodel == mdPixel) {
     for(int i=ofs; i<ofs+cnt; i++) {
@@ -418,6 +424,24 @@ void addpoly(const transmatrix& V, const vector<glvertex> &tab, int ofs, int cnt
     return;
     }
   tofix.clear(); knowgood = false;
+  if(among(pmodel, mdPerspective, mdGeodesic)) {
+    if(poly_flags & POLY_TRIANGLES) {
+      for(int i=ofs; i<ofs+cnt; i+=3) {
+        hyperpoint h0 = V * glhr::gltopoint(tab[i]);
+        hyperpoint h1 = V * glhr::gltopoint(tab[i+1]);
+        hyperpoint h2 = V * glhr::gltopoint(tab[i+2]);
+        if(!behind3(h0) && !behind3(h1) && !behind3(h2)) 
+          addpoint(h0), addpoint(h1), addpoint(h2);
+        }
+      }
+    else {
+      for(int i=ofs; i<ofs+cnt; i++) {
+        hyperpoint h = V * glhr::gltopoint(tab[i]);
+        if(!behind3(h)) addpoint(h);
+        }
+      }
+    return;
+    }
   hyperpoint last = V * glhr::gltopoint(tab[ofs]);
   bool last_behind = is_behind(last);
   if(!last_behind) addpoint(last);
@@ -1614,7 +1638,12 @@ void dqi_poly::draw() {
       coords_to_poly();
       color_t col = color;
       if(poly_flags & POLY_INVERSE) col = 0;
-      svg::polygon(polyx, polyy, polyi, col, outline, get_width(this));
+      if(poly_flags & POLY_TRIANGLES) {
+        for(int i=0; i<polyi; i+=3)
+          svg::polygon(polyx+i, polyy+i, 3, col, outline, get_width(this));
+        }        
+      else
+        svg::polygon(polyx, polyy, polyi, col, outline, get_width(this));
       continue;
       }
   #endif
@@ -1644,7 +1673,11 @@ void dqi_poly::draw() {
         }
       filledPolygonColorI(s, polyx, polyy, polyi+5, color);
       }
-    else  
+    else if(poly_flags & POLY_TRIANGLES) {
+      for(int i=0; i<polyi; i+=3)
+      filledPolygonColorI(s, polyx+i, polyy+i, 3, color);
+      }
+    else
       filledPolygonColorI(s, polyx, polyy, polyi, color);
   
     if(current_display->stereo_active()) filledPolygonColorI(aux, polyxr, polyy, polyi, color);
diff --git a/floorshapes.cpp b/floorshapes.cpp
index 359ed96e..1dabc4f7 100644
--- a/floorshapes.cpp
+++ b/floorshapes.cpp
@@ -1086,6 +1086,7 @@ void draw_shape_for_texture(floorshape* sh) {
 /** copy the texture vertices so that there are at least qty of them */
 EX void ensure_vertex_number(basic_textureinfo& bti, int qty) {
   int s = isize(bti.tvertices);
+  if(!s) return;
   while(isize(bti.tvertices) <= qty) {
     for(int i=0; i<s; i++) bti.tvertices.push_back(bti.tvertices[i]);
     }
diff --git a/hypgraph.cpp b/hypgraph.cpp
index 89ae6155..f060efea 100644
--- a/hypgraph.cpp
+++ b/hypgraph.cpp
@@ -165,7 +165,7 @@ ld find_zlev(hyperpoint& H) {
   }
 
 ld get_tz(hyperpoint H) {
-  ld tz = euclid ? (1+vid.alpha) : vid.alpha+H[LDIM];
+  ld tz = vid.alpha+H[LDIM];
   if(tz < BEHIND_LIMIT && tz > -BEHIND_LIMIT) tz = BEHIND_LIMIT;
   return tz;
   }