A collision mesh is an invisible mesh which is used for the collision detection of vehicles, playertypes, or any other modeled entity. It can be included in the .dts directly.
The collision mesh of the default jeep.
Overview
Collision meshes in Torque are convex, generally low polygon shapes which can be an approximation of the model. In most cases, collision meshes are just boxes fit to the general size of the object, but with more complex objects like large vehicles, a more detailed mesh is recommended.