[ODE] Relation between mass, gravity and step size

[Michael Merz]

Dear subscribers,

I investigate whether ODE could be helpful to implement in an AR-system
(augmented reality) to simulate real physics. It's a project I'm running
here at Fraunhofer IGD. 'Playing' around a bit there raised some questions.
Would be great, if someone could help me!

1. If I change just the sWorldStep the mass (or/and the gravity) seem to
change as well. Why and how is it changing?
2. To construct a real world model I need to simulate the gravitational
force of the earth. What's the unit of mass? If I set dWorldSetGravity
(world,0,0,-9.81) in the example test_buggy it does not look real at all.
3. Is there a possibility to give objects properties such as elasticity or
surface condition?
4. The 'jittering' and the 'explosions' that happens sometimes is not
avoidable, isn't it? Where does it come from? How can it be reduced?

Thanks a lot in advance.

Michael