Strange collision responces


I have had great success playing with the jmePhysics libraries, but have hit an issue I can't explain.  The 3ds objects colliding with other prefabs works fine, but if I place one of the vehicles in the scene and have it land on his level (however simple it may be), it will not settle on the object.  It will bounce around lightly, never coming to a stop like it would on a default physics block.

What's more, if he makes a simple arena with walls, the objects will begin to react more irregularly.  Are concave objects an issue in jmePhysics?

Your help and input is greatly appreciated.

FYI: A friend of mine is developing simple levels in 3d Studio Max and is exporting them to me in the 3ds file format.

Do you use triangle accurate collisions for the model? If yes, that could be the reason. ODE restricts the number of contacts per geom and chooses the contacts to discard randomly. I would recommend to avoid triangle wherever possible - at least for dynamic stuff. You could increase the allowed contact points, but then you'd run into performance problems.

To check what's going on enable the physics debug mode and have a look at the contact points (cyan crosses iirc).

Thanks for the quick response.

Would using lower poly collision models help this issue? Also, if you don't use triangle accurate collisions, do you use a combination of primitives made up to fit the object, or what?  Some of my objects will be a little irregular, and would love some input on what other people use on their projects :slight_smile:

rokkun said:

do you use a combination of primitives made up to fit the object, or what?