Collision filter groups and masks at the collision shape level
I was trying to filter collisions by shapes instead of by object, using collision groups and masks.
It was not so dificult to find a place to check whether a collision shape needed to be processed in the source code, I also added that feature to the ray cast test code.
The result is that I now create a compound shape by specifying the group and mask for each child shape, then create the rigid body specifying its group and mask by a bitwise or operation of all the children shapes
So, my question is if something like this could be added to bullet physcis by default.
I'm looking for ways to optimeze the library for movile devices, and this feature save the need to work with constraints when there is a need to filter collisions in different parts of the same body, it would avoid to test most child chapes too in a ray test, asking what shapes need to be tested first, by their collision shape flags.