diff --git a/cell.cpp b/cell.cpp
index 75b5c86a..c805d3bb 100644
--- a/cell.cpp
+++ b/cell.cpp
@@ -521,6 +521,33 @@ EX int celldistAlt(cell *c) {
   return mi;
   }
 
+/** direction upwards in the tree */
+EX int updir(heptagon *h) {
+  if(bt::in()) return bt::updir();
+  if(WDIM == 3 && reg3::in_rule()) {
+    for(int i=0; i<S7; i++) if(h->move(i) && h->move(i)->distance < h->distance) 
+      return i;
+    return -1;
+    }
+  if(h->distance == 0) return -1;
+  return 0;
+  }
+
+/** direction upwards in the alt-tree */
+EX int updir_alt(heptagon *h) {
+  if(euclid || !h->alt) return -1;
+  if(WDIM == 3 && reg3::in_rule()) {
+    for(int i=0; i<S7; i++) if(h->move(i) && h->move(i)->alt && h->move(i)->alt->distance < h->alt->distance) 
+      return i;
+    return -1;
+    }
+  for(int i=0; i<S7; i++)
+    if(h->move(i) && h->move(i)->alt == h->alt->move(0)) 
+      return i;
+  return -1;
+  }
+
+
 #if HDR
 static const int RPV_MODULO = 5;
 static const int RPV_RAND = 0;
diff --git a/pattern2.cpp b/pattern2.cpp
index 3627f78c..1a6e2fd4 100644
--- a/pattern2.cpp
+++ b/pattern2.cpp
@@ -2543,13 +2543,8 @@ EX namespace linepatterns {
   linepattern patTree("underlying tree", 0x00d0d000, cheating, 
     ALLCELLS(
       if(is_master(c)) {
-        int dir = bt::in() ? bt::updir() : 0;
-        if(WDIM == 3 && standard_tiling()) {
-          for(int i=0; i<S7; i++) if(c->move(i) && c->move(i)->master->distance < c->master->distance) {
-            dir = i;
-            break;
-            }
-          }
+        int dir = updir(c->master);
+        if(dir == -1) continue;
         cell *c2 = c->master->move(dir)->c7;
         if(gmatrix.count(c2)) {
           if(S3 >= OINF)
@@ -2562,7 +2557,9 @@ EX namespace linepatterns {
     );
   linepattern patAltTree("circle/horocycle tree", 0xd000d000, cheating, 
     ALLCELLS(
-      if(is_master(c) && !euclid && c->master->alt) {
+      if(is_master(c)) {
+        int dir = updir_alt(c->master);
+        if(dir == -1) continue;
         for(int i=0; i<S7; i++)
           if(c->master->move(i) && c->master->move(i)->alt == c->master->alt->move(0)) {
             cell *c2 = c->master->move(i)->c7;