Submitted by , posted on 09 October 2000
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Collision fun in cube hell :
This is a little demo of my collision detection library, called Z-Collide. First
of all, I guess the pic will get reduced, and you may not see what's going on
here. So have a look at the original screenshot:
The upper left image contains 10000 cubes ready to be tested against the
collision detection module, down to the triangle level, and including closest
points computation while we're at it. No fear.
The upper right image shows 4096 of them in the worst possible scenario:
randomly placed within a unit cube, colliding in all possible ways. The profiler
keeps track of what happens at various levels and reports the number of cycles
it takes to do the job.
The lower left (pretty confused) image shows the same kind of situation, with
AABBs (Axis-Aligned Bounding Boxes) turned on. Green boxes are not colliding.
Yellow boxes are colliding, not the actual cubes. Red boxes are colliding, and
the cubes within as well.
The last image focus on a single pair. A white segment is drawn between two
user-selected cubes, reporting their closest points, exact distance, and the
contact manifold (Point-Point, Edge-Edge, Point-Face, etc). That contact
manifold is very important for collision response, when the collision detection
library is used as the heart of a rigid body simulator.
You can download the demo: www.codercorner.com/CubeHell.zip
The included readme file contains some more technical information.
On my Celeron 500 / GeForce / W98, it runs at 60~80 fps for 1024 cubes (which
would need one million intersection tests with a naive O(n^2) way). Needless to
say, the framerate drops for 10000 cubes (2~10 fps).
Of course, the lib works for arbitrary models, not just for cubes :)