Gerard Tyra - SA Technology (gtyra++at++cts.com)
Fri, 25 Apr 1997 09:01:50 -0700 (PDT)
> Hello!
> I'm a new user of IRIS Performer and I have to make holes in the ground
> with an excavator. I don't see how I can draw them (with pfGeoSet, what about
> intersections with the new ground ...?).
> Could you give me your ideas?
> Thanks.
Francois,
Before you ask "how", think about "why?" Who is going to be using this
visual, and for what purpose? How much visual fidelity do they need?
Do you want to show a blade or bucket making contact with the ground and
then a hole appears? Or do you need to see the teeth marks left by the
bucket and the loose soil left behind in the hole?
As for "how", you can either use predefined geometry or immediate mode
graphics. For the predefined geometry, you have a large number of
surfaces stacked to represent the gound. Surface layers are turned off
as the dirt that they represent is removed. Layers below the current
surface have to be turned of to reduce depth complexity. If you use
immediate mode, you can do anything that you can imagine.
In either case, this type of visual can become transform bound very
easily. The use of textures will help for fine detail effects, but most
of what you want to do will probably be done in geometry.
Gerry
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