Nicolas Gauvin (nicolas++at++cae.ca)
Fri, 20 Sep 1996 14:54:25 -0400
Collision detection in Performer is currently based on line segments
and hierarchical bounding volumes (spheres and axis aligned bounding boxes).
This works well for things like terrain following where you are intersecting
a small number of line segments with your database. However it is not well
suited for volume to volume collision detection.
Especially if you have a large number of volumes to test and those volumes
are close to each other.
An interesting article was recently published on this subject in the
Siggraph 96 proceedings:
OBB-Tree: A Hierarchical Structure for Rapid Interference Detection ,
S. Gottschalk, M. C. Lin and D. Manocha
They propose an efficient and accurate way of doing close volume to volume
collision test using oriented bounding box trees build from triangles composing
volumes.
You can check their web pages to find a postscript version of this
article as well as a C++ library called RAPID implementing this
scheme.
http://www.cs.unc.edu/~geom/OBB/OBBT.html
I have used this library to add volume to volume collision detection capability
to Performer. It gives very good results especially
when doing all the collision processing in a separate ISECT process.
--
Nicolas Gauvin CAE Electronics Ltd., 8585 Cote De Liesse
Software Developer Saint-Laurent, Quebec, Canada, H4L-4X4
3-D Graphics Applications tel: +1 514 341 2000 extension 2275
nicolas++at++cae.ca fax: +1 514 340 5496
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