[ODE] non static deltaTime in the step (worldStep(world,deltaTime) instead of worldStep(world,0.05)) => problem?

[J. Perkins]

Frédéric Marmond wrote:

 > The problem is that when deltaTime is too small, the ODE is very 
instable.
 >
 > So, I introduced a little loop to slow down the prog.
 > deltaTime is bigger, and the ODE is ok.
 >
 > When i say that ODE is instable:
 > I use only one body, without force.
 > It start at Z>0.0 => it falls.
 > I only detect collision when it touch the Z=0 plane (ground)
 > After a bounce, it stabilize at this position (touch the plane Z=0)
 >
 > But, after a while, it moves again, and make a great jump (unless 
its mass is
 > 800 and the gravitation is -9.81!!!)


I had a similar problem for a while. I traced the problem down to
the fact that I was running ODE at 500Hz and my collision detection
at the frame rate (roughly 100Hz).  When I ran the collision
detection at the same rate as the physics, the problem went away.

Since the subject has come up - is there a way to run the collision
detection at a lower frequency than the physics? Should my split
frequency example have worked?

Jason
379