Changing the CG of a shape using Compound shape

[chucksspencer]

I'd like to be able to change the center of gravity of a shape. One solution I've seen for this is to add the shape to a compound shape (containing only the initial shape) and using the compound shape's child transformation to offset the CG.
That's how it seems to be done in the vehicle demo.

My question is: is it wise to do this a lot? Is it much more expensive to simulate a compound shape containing a single actor than it is to simulate that single actor independently?

- Chuck

[Erwin Coumans]

Yes, the btCompoundShape the most appropriate way to shift the center of mass. The performance isn't very different, and the overhead of the btCompoundShape is orders of magnitude smaller than the actual collision detection cost.

Thanks,
Erwin