a quick and fast way 2 fake per poly collision detection is 2 use hit boxes. the idea is this...

calculating each and every finger in ur hand for collision detection is not likely 2 produce any noticeable difference (other than decrease the framerste).
do why not use a cube hitbos each for ur arm and hands...

even half life 1 engine of 1997 supports it. Why not 3dgs?

This technique is used in MythicAI to make it possible to have different hitpoints (arms, leg, head, shoulders, etc.)

You can use it to simplify the collision detection if your model has a high poly count.

It is up to you to use this idea, but computers have more horsepower than anno 1997. The question is if it is still required to go this way of optimization...

Think about early 3d games. They had to store sin/cos data in tables to speed up the game. This is not needed any more and it was not accurate...

-- slacer