[ODE] Non-deterministic behavior

Joe Ante joeante at liquiddestiny.com
Sun Aug 24 10:46:01 2003


> Does anyone have experience with ODE giving non-deterministic
> results?  What I mean is specifically this:  We have a simulation where you
> shoot a ball out over a terrain and it starts rolling from there.  The only
> user input is the direction/spin/force that the ball is launched with --
> and all these are set with discrete controls. The collisions in this case
> are all between spheres and triMesh.  We have found that the ball does not
> in a deterministic manner -- but rather bounces oddly sometimes, sometimes
> acts as expected.  This is sometimes worse if there is friction in the
> collision contact, but even for frictionless collisions it still reacts in
> a non-deterministic way.  Does anyone have any ideas about this one, seen
> this behavior themselves?  I saw the posting regarding friction causing
> unexpected results -- this is a different problem.
I ran across something similar, where I had set the bounce factor in the
collisionSurface struct but forgot to set the bounce_vel.

Je Ante