[ODE] Mismatching results / non-deterministic behaviour

[Jean de Largentaye]

Well there's also something else: different machines have different
floating-point precisions, and this will also effect determinism. It's
especially a problem if you're trying to run ODE in a networked
situation (online game). The solution is to have complete control over
the precision of your processor's FPU*, which can be problematic if
you're using DirectX
(http://opende.sourceforge.net/wiki/index.php/FAQ#I_use_DirectX.2C_and_it_seems_like_ODE_has_switched_to_single-precision.21)

On a side note, is this last bit about DirectX switching to
single-precision still true with the latest versions? I'm an OpenGL
guy, so I wouldn't know...

*easier said than done, I know, hopefully Google can help you :)

John

On 9/14/06, Hauser Dietmar <D.Hauser at dion-software.com> wrote:
>
> That also explains, why results were the same, when being run on
> different machines, because the ODE random number was never
> initialised and therefor using the same predefined seed.