[ODE] Newbie question about composite bodies

[Tristan McMillan]

Hi

I am tying to represent a truck by two blocks in a composite body,
however, the maths seems to be throwing me off. As I know the general
centre of gravity of the whole combination but I don't know how to
relate the mass of each block to the main centre of gravity.

I have been trying to calculate a mass distribution that will meet the
overall CG position but this has proven unsuccessful as my truck always
goes unstable.

I've had a look at the ODE Wiki example for composite bodies, and
understand it except for the part where they use boxoffset to move the
mass to (0,0,0).

I would appreciate any help on this,

thanks
Tristan