Collision mesh

A collision mesh (sometimes collision model, though it is actually only ever a component of a model) is a cheap 3D mesh used by Source to calculate VPhysics collisions.

A collision mesh is not visually represented to the player, and should be extremely low-detail compared to any reference or LOD meshes - see the images to the right for two examples. The lack of precision will not be noticed, except in that it doesn't grind the simulation to a halt!

There is one major restriction with collision meshes: like brushes, they must be convex. Multiple collision meshes can be used in the same model however, so this is rarely if ever an insurmountable problem.

See also

• Physics and Ragdolls
• $collisionmodel - QC command for collision meshes without moving parts
• $collisionjoints - QC command for collision meshes with moving parts