[ODE] Combining inertias

[Russ Smith]

> Not specifically an ODE question: how does one combine the
> inertias of different bodies? Say I have two boxes connected by
> a cylinder. I have inertias for all three, but now I need to
> combine them into a single rigid body. Can I just add the
> components of the inertia matrices?

yes - but getting the updated center of mass is more tricky.
there is an ODE function to do this:

	void dMassAdd (dMass *a, const dMass *b);

check the latest (CVS) docs. also look at the test_boxstack
example, which uses this function for its composite objects.

russ.

--
Russell Smith
http://www.q12.org