btCompoundShape vs. btGImpactCompoundShape?

[kate]

Hi,

I just wondered if anyone had done a comparison of Bullet's own btCompoundShape, vs. the GIMPACT btGImpactCompoundShape/btGImpactConvexDecompositionShape - in particular, for convex decomposition. They both seem to serve the same purpose... so is one faster? More stable? Simpler to implement?

I'm trying to work out which one to use and am feeling too lazy right now to try to implement both

Thanks!

Kate

[Erwin Coumans]

It is best to just use the btCompoundShape.

We added GIMPACT because of btGImpactMeshShape, but it came with btGImpactCompoundShape/btGImpactConvexDecompositionShape too.

btGImpactCompoundShape/btGImpactConvexDecompositionShape will be likely deprecated in a future release.
Thanks,
Erwin

[kate]

Hi Erwin,

Thanks for clarifying (again!); I thought that might be the case but saw that some people on here had mentioned using the GIMPACT version, so wondered if there was a reason to do so. I'll stick with btCompoundShape.

Kate

[sparkprime]

I tried the decomposition gimpact shape but I found it to be very unstable. However it seems to work in the demo for the rabbits so it may be my triangle meshes are unsuitable. I didn't track the problem down as the standard gimpact triangle mesh seemed to work very well.

If possible I would be using a Bullet compound of standard Bullet shapes though. I have a very nice bowling pin that's made out of a cylinder, 2 spheres and a cone. It's very fast and behaves very realistically.