[ODE] slider trouble

[Russ Smith]

> I've attached another test that bounces things off
> the ground a bit differently, and you can watch two blocks bounce
> skyward and then gradually spin up to an explosion.

i'm chalking this one up to integrator error - if you lower the
timestep, the effect disappears. i'm pretty sure that there are no
non-physical forces being applied to the system (as was the case with
your previous slider-stop problem). unfortunately this kind of thing
(integrator error) is unavoidable with ODE's current integrator in some
situations where you have rapidly rotating bodies.

> Also, could this problem be related to the problem where a single
> flying spinning body also gains angular momentum?

yes, it's the same kind of thing. i'll do some more experiments and see
if something can be done about this.

in the meantime, use a smaller timestep, or less bounce, or larger mass
- anything to reduce the amount of rotation experienced per time step.

russ.

-- 
Russell Smith
http://www.q12.org