Unity Game Optimization - Third Edition

Avoiding inter-ragdoll collisions

The performance cost of ragdolls grows exponentially when they are allowed to collide with other ragdolls. In fact, any joint collision requires the solver to calculate the resultant velocity applied to all of the joints connected to it, and then each of the joints connected to the other ragdoll. That means, in practice, that both ragdolls must be resolved entirely multiple times. Moreover, it gets significantly more complicated if various parts of the ragdolls are likely to collide with one another during the same collision.

This is a tough task for the solver to handle, so we should avoid it. The best way to do this is to use the Collision Matrix. It is wise to assign all ragdolls to their own Layer and ...