Rigid Body System: Support for Hair-Like Objects that Should Only Collide with Body, Not Each Other

In Blender's rigid body simulation system, objects in the same collection always collide with each other. This creates a problem when simulating hair strands or accessories that are attached to a character.

In other software such as Unreal Engine, it's possible to set up rigid bodies so that hair strands collide with the character's body but not with each other. This is important for realistic animation and avoiding unnatural collisions between neighboring strands.

Currently in Blender, if I add both the hair and the body into the same rigid body collection to enable body collision, the hair objects will also collide with each other, which is usually undesirable. Adding them to separate collections avoids inter-hair collision, but then they won't collide with the body either.

It would be great if Blender could support a more flexible collision filtering system for rigid bodies, allowing control over which objects can collide with which—so that hair can collide with the body but not with other hair strands.

This would greatly improve usability for character animation and complex simulations.