CompuServe Thread

Lightwave–Boolean Drill

5 messages in this thread
#76021From: Stephen K. PooleMar 2, 1994 6:10 PM
Sometimes when using the Boolean Drill operation, polygons behave strangely. Sometimes they flip for no reason, sometimes they disappear completely. For example, While modeling an alien I used the Boolean Union drill to attach his nose. After my amiga crunched its numbers, the nose was attached, but to nothing. All of the polygons around the nose on the face had vanished. Also several random polygons all over the alien had vanished, and some had flipped. What is causing this, is it a bug or am I doing something wrong. Michael A. Painter
#76156From: Jim S. RoofMar 4, 1994 9:01 AM
Well, this might not be the answer that you are looking for but here goes! The boolean functions require absolute topographical integrity to work properly. If you were to create two spheres that you needed to join and one of those spheres had a hole in it about the size of a gnats eyelash it will not work. That object has ceased to be a spherical solid and is now only a shell. When the boolean is done it all gets screwed up. Try this – make sure that the head is a complete solid (no hole for the neck, eyes, mouth… nothing), then make sure the same is true for the nose (no nostrils, just like hayfever season). This should fix it. If not, I would be somewhat surprised. Also make sure that the normals are all correct before starting and do not double your polygons. If you have doubled polygons then you have created a "shell" without going to the trouble of creating a hole.
#76483From: Christopher LapriseMar 8, 1994 11:59 PM
When you say "doubled" polygons, don't you mean "tripled"? -Chris
#76519From: Jim S. RoofMar 9, 1994 1:10 PM
Nope. Doubled polygons are those which share identical points but in fact are two polys which have two normals facing in opposing directions. Some of the objects imported from Imagine models have their polys doubled. This assures that no polys will be flipped the wrong way but it eats memory and in the case of Boolean functions, gets things all awry. Jim
#76336From: Anthony E. ThomasMar 6, 1994 7:37 PM
NON-PLANAR polygons might also be the culprit. Try going into the display menu. With Polygon selected hit the STATS button. From the STATS Requester hit the NON-PLANAR button. This will select all the NON-PLANAR polygons. After they are selected and are yellow, triple them. Repeat the step until you remove all NON-PLANAR polygons. This trick has helped me many times…..! Good Luck!!