Silly title, I know.
I'm not sure how to achieve this, and I'm sure a PG is not necessary, if this functionality actually exists.
Imagine the simple and common version of a FPS-setup.
You have a camera, and a mesh or more in front of this camera, usually a couple of hands and a gun of some sorts.
Now, when I hit a wall face-first, part of the hands/gun model will clip through the wall, and we sure don't want that to happen.
Is there some way to always render the hands/gun models in front of everything else, igoring depth? I looked at z-index, renderingGroups and masks without luck.