Can you apply physics to only part of an object?

I have a character, who wears a robe. Actually he is almost nothing but a robe, and a mask, so the character itself is actually a robe.

Because of this, I want to make his sleeves act like cloth, instead of his whole body. I have in blender divided his sleeves into vertex groups, if this is of any help.

Are there any way to apply physics to only part of an object?

If you added bones to the robe – might look like a bat-wing skeleton – you could hand rag-doll it. Give them all big, overlapping envelopes. To rag-doll by hand, each bone gets a rigidbody, a collider and a characterJoint or hinge to its parent bone. I’d imagine you could make a dummy Kinematic-RB parent as the root, childed to the body. That would give them something legal to latch onto, and keep them from “pulling” the body.

For sleeves to flap nicely…there’s probably a whole art to it. I’d imagine maybe 3 bone chains down the length. Constraints on the joint rotation might keep them from pulling the sleeve off the arm.

Creating the bone envelopes automatically creates vertex groups – it puts each vert in the bone that has the most influence on it. I don’t think having vert groups already will really help.

This is what you’re looking for.