Collision demo
by Ingemar Ragnemalm
This is a set of similar demos showing how to make simplified collision
detection and handling, based on spherical animated object and static
convex polyhedra. If you need something more complex than that, maybe
you should try a physics engine.
0. Interactive collision detection with no dynamics
This first example only shows how collision detection works. A single
sphere can be moved by WASD keys, and if it collides with the
polyhedron, it is moved away.
1. Collision detection and handling, many spheres and one polyhedron
This demo shows a number of spheres bouncing off each other and a
polyhedron. Thus, basic physics is handled and it workd pretty well.
However, this is a simple case.
2. Surfaces
A number of spheres are bouncing down a few planes. This is a case
where this simplified system works really well. It is hard to see any
cases that fail.
3. Pile
This example shows a case where our model is not sufficient. The failure is
intentional; I want to show what the limitations are. Piling things on
top of each other is a typical case where simplified physics fail. In
this case, we don't get any problems with stability, but the positions
of the spheres are not pretty.
4. Nasty
The final case is one where we get less problems than expected. The
case is the chute, two planes that narrow with a steep angle. Even
full-fledged physics engines have had problems with this. I provided
two cases, one which works well despite fairly steep slope, and one
even worse where some errors are visible.
A real physics system would add a lot to this. The first improvement to
add would be data structures to improve performance for large worlds,
e.g. octrees or similar.
What the demo needs most of all to be really nice is shadows, but
shadows is not the focus of the demo. That is why there are none.
collision-demo.tar.gz
by Ingemar Ragnemalm 2012-2013