art_guide.doc wrote:Collision Primitives are a cheaper and faster way of computing collision for the game engine.
It is also the only way to have collision on moving parts such as turrets or bones.

Collision primitives can be either cubes, cylinders, or spheres.
Cubes can be scaled in x,y, and/or z to better fit the geometry they are conforming to.
It is best to leave the original size of 8 units as is and scale the cube from there.
On the other hand, cylinders and spheres CANNOT be scaled.
Instead, use the polygon properties such as radius and length to control the size of those 2 primitives.

Also very important, primitive collision pieces CANNOT be frozen or lose their primitive properties.
This information is taken directly into the game engine and if it is lost, the engine will most likely ignore the primitive collision.
Lastly, DO NOT move the center of primitive collision either or else the proper information will be lost as well.