[ODE] numerical stability (sort of)

[Jeffrey Smith]

--- tbp <ode at ompf.org> wrote:
> contrary to gcc 3.4 built dll, msvc 7.1 ones (my own builds) don't
> even allow reproduceable runs within the same session (that is
> destroying box bodies+geoms and simulating again gives different
> result).

We have perfectly (to machine precision) reproducable results with ODE
on both Windows (using MSVC 6.0) and Linux (gcc 3.4).  The important thing
is that your simulations have EXACTLY the same inputs.  Collision of multiple
objects is chaotic so even small (just a few of the least significant bits)
differences in object positions or velocities can cause your simulations to
diverge.

-jeff