[ODE] body geometry dualism

[Russ Smith]

> Bodies are for physics, geometries are for collsion detection. You
> don't have to have both but when you do they behave as one 'entity'.
> So when you attach a body to some geometry they share the same
> position etc. You don't have to set both.

more fundamentally, physics and collision detection are two separate
activities, so it's nice to have some kind of interface between them, so
that either can be replaced. from a simplicity point of view having a
single object would be nice, but from a flexibility point of view the
separation into two objects is better.

russ.

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