[ODE] Tetrahedron - found it

[Gary R. Van Sickle]

> > Wow, that's by far the best reference on the subject that I've seen to
> > date.
> > Thanks!
> 
> Glad you liked it, it took me hours of prowling the net to find it ;) 
> Any chance anyone on the know could implement those for ODE? Even though 
> ODE doesn't support the colission shapes, it would be cool to have the 
> masses. Complex shapes can be aproximated with the goems evailable in 
> ODE, and so could simple masses I suppose. But adding the correct 
> inertia information couldn't hurt...
> 

If you have Ix, Iy, and Iz values, your inertia tensor is:

[ Ix  0  0  ]
[  0 Iy  0  ]
[  0  0  Iz ]

-- 
Gary R. Van Sickle
Brewer.  Patriot.