[ODE] 3 beginner questions

[Bob Ives]

Hi.  I´m just starting out integrating Ode into our game engine.  So far I find the api clean and comfortable to work with. But I
have a few beginner type questions that I cannot find answers to either in the latest manual, searching the list, or in the
community FAQ.

1. HashSpace levels....  how should I apply a knowledge of typical object sizes and/or world space size to the call
dHashSpaceSetLevels() ?  Is the rule maybe that 2^minlevel <= smallest object dimension and 2^maxlevel <= biggest world space size,
or something else completely...?

2.  Drag.  After implimenting simple drag as described in the wiki faq, I found that objects still take a considerable time to come
to rest after colliding, despite increasing the drag coefficients.  I thought to experiment with the density argument I give in
dMassSetSphere, but surprisingly found that increasing density leads to the object slipping for more time before coming to rest, and
vice-versa.  I also found that with more density there was a contant interpenetration of my objects sphere with the ground plane.  I
wonder if the slip is somehow caused by a longer time resolving contacts between the ground and the moving body.

3.  Finally I was wondering about replacing my ground plane with a box that contain the action.  My first try leaves all objects
pushed quickly to the outside of the box. Is there a way to invert this behaviour...?   I thought this was being done in the buggy
demo, but if so the method escapes me.

Thanks for any advice,

Bob Ives