--- libgender/oct.C	2004/11/07 02:28:18	1.71
+++ libgender/oct.C	2004/11/07 03:05:41	1.73
@@ -9,7 +9,7 @@
 #include "view.h"
 #include "entity.h"
 
-enum visibility_state { FULL, PARTIAL, SMALL, OCCLUDED };
+enum visibility_state { FULL, PARTIAL, SMALL, OCCLUDED, SUBTREE_OCCLUDED };
 
 struct evis {
   visibility_state state;
@@ -158,6 +158,12 @@
     ctx.nc_far = max (ctx.nc_far, z);
 #endif
 
+  if (vs.state == SUBTREE_OCCLUDED)
+    {
+      ctx.vislist.push_back (this);
+      return false;
+    }
+ 
   // node to start with
   unsigned char si = centeri.x > 0 ? 1 : 0
                    | centeri.y > 0 ? 2 : 0
@@ -167,7 +173,7 @@
   static unsigned char toggle[8+1]
     = { 0,  0^1, 1^2, 2^4, 4^3, 3^5, 5^6,  6^7, 0 };
 
-  bool visible = vs.state == PARTIAL || vs.state == FULL;
+  bool visible = size () && (vs.state == PARTIAL || vs.state == FULL);
 
   unsigned char *next = toggle;
   do
@@ -186,7 +192,7 @@
     }
   else
     {
-      vs.state = OCCLUDED;
+      vs.state = SUBTREE_OCCLUDED;
       ctx.vislist.push_back (this);
     }
 
@@ -197,7 +203,7 @@
 {
   oct_visibility &vs = *(oct_visibility *)get_visibility (ctx);
 
-  if (vs.state == OCCLUDED)
+  if (vs.state == OCCLUDED || vs.state == SUBTREE_OCCLUDED)
     {
       if (ctx.pass_type == view::POSTDEPTH)
         {
@@ -243,7 +249,7 @@
                   ctx.nz_far  = max (ctx.nz_far,  z + extent);
                   ctx.nz_near = min (ctx.nz_near, z - extent);
 
-                  if (ctx.pass_type == view::DEPTH || evs.last + 0.3 > timer.now)
+                  if (ctx.pass_type == view::DEPTH || evs.last + 0.1 > timer.now)
                     e->draw (ctx);
                   else
                     {