[ODE] Jitters

[Tim Rightnour]

Hello all,

I'm a new user to ODE, and am currently integrating it in my open-sourced game
( http://www.genecys.org ).

After lots of fiddling, I got my simulation mostly stable, and decided to try
using WorldQuickStep instead of WorldStep to save CPU.  Right now my simulation
is basically a dTerrainY, and a few boxes sitting on it.

With WorldStep, within about 5-10 iterations of the loop, the two objects
settle out and sit still.  When I changed the code to use quickstep, one of the
objects settles out, but the other one jitters forever, slowly rotating about
the X and Z axes.

Reading the list archives, I decided to implement damping on the bodies with
the code that was posted earlier.  Basically the *= -0.01 on each of the
angular and linear velocity components.  Doing so instantly caused my jittery
object to explode off into space, regardless of if I was using WorldStep or
QuickStep.

I'm a bit confused what to do now.  I allready have ERP and CFM set pretty
leniently, as I don't care too much about squishiness:

    dWorldSetERP(mapg->world, 0.2);
    dWorldSetCFM(mapg->world, 0.01);

Any advice would be appreciated.  I'm using ODE from CVS as of today, with
float precision.  Also, my stepsize is 0.05, which is about as low as I'd like
to take it, for performance reasons.  MAX_CONTACTS is set around 30, and the
box in question is generating about 5 (give or take during jittering, but when
stable it sits at 5).

---
Tim Rightnour <root at garbled.net>
NetBSD: Free multi-architecture OS http://www.netbsd.org/
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