Backpack modelling advice

Hello all,
Does anyone have any advice on how to model a backpack for a human character? I have modeled one for my rigged character, and it looks nice in the rest position, but my character is rigged, and when I modeled my backpack, I did it as a separate mesh and then joined the two objects together. Now when I pose the character, the body mesh swallows the waist straps when he bends forward at the waist, or twists from side to side.

Anyone else have any success doing this correctly? I’d love to hear how you did it. FYI, I am trying to keep this as lowpoly as possible to use in BGE.

Thanks,
Mike

You could set it as a cloth material, but you shouldnt add it straight to your mesh, I would add it to the bone rig, and then use the body mesh as a collision, that way the cloth doesnt go through the body, but follows it correctly