That’s cool! Interesting how raycast can do volume point scatter. There was a patch for volume point scatter but I don’t think it’s alive. I have been using multiple solidify modifiers to create multiple surfaces in the volume and point distribute on them. It’s cool to see another way to do it.
This is how I do it with solidify modifiers, by the way, I am looking forward to the solidify node patch to commit, then I can do it in the node graph.
EDIT: Just tested my method with monkey head, solidify does not work well with its ear so my result is kind of weird. You method is better! 