physics on chain-like objects

I’m trying to put a couple of keys (and I mean keys that are used for opening locks) in a keyring and drop them on a surface with the physics engine but I’m having problems.

I have set the keys and ring to rigid bodies, radius to 0.01 and the bound type to ‘convex hull’ the rest of the setting are the default ones. When going to the game engine the objects get thrown away from each other and passing right through each other.

I’m attaching a .blend to make the problem more clear (This is not the actual project, just an example of the problem I’m having)


physics_problem.blend (230 KB)

well if you want the ring to go through the hole in the key… you need to set the collision bounds to triangle mesh on both the key and the ring… this collision bound works with objects that have holes in them. It basically makes a triangle mesh out of the entire surface… holes included… but it is quite computationally expensive.

Oh and don’t mess with the radius setting too much it used for controlling the size of the sphere bounds.

If you find it too slow… there are ways of faking it.

Thanks a lot. I’m only using this for a still image so the computing times aren’t really a problem