Lightwave–Boolean Drill
5 messages in this thread
(I'm posting this for a friend at work who's learning Lightwave. I've already
posted this once on the NEW TEK section of Amiga Vendor forum, and got the
reply included in this note. Any further insight would be appreciated.)
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[ORIGINAL MESSAGE] 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
[REPLY] 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.
Hope this helps.
Jim
One thing I have found that really helps is to only work with the polygons
that are going to be changed. In your case, Cut the section of the alien's
face that gets the nose (the forhead, right?) and put it in a blank layer, then
put the nose in another blank layer and do your Boolean functions using just
these two temporary layers. I find the results much more predictable when I do
this.
Mike McCormick
Actually,
you don't even have to cut the polygons out. As long as they are selected,
the boolean function will only operate on those selected.
JG
The problem I have with doing that is that sometimes I don't like the result
I get the first time. For example I'll try to use Add and I find out that I
should have used Intersect. When I hit the Undo key and try it again, I always
forget to reselect the polygons I want to effect (as they were de-selected
during the operation).
Mike McCormick
If you select the volume button and use the right mouse button to lasso
the area desired you can achieve the same effect without having to paste
to another layer.
GT