Dude you are right on point! I was talking about doing a GPU picking method for that and was trying to see if there was a hacky way to do it like that. You suggesting that give me lots of hope. The other method I was going to try to work out was to make a shader that calculates a signed distance function that represents the mesh parts then have it ping-pong the results back to the CPU but that seems like it would take some wizardry. This texture based pick method might be the ticket!