[ODE] Jitters and GeomTransforms

[matt stephure]

Hi all,

I'm working on a multiple robot simulator project. I'm currently
having the following problem with ODE.

I'm using a spring/dampening friction style (CFM/ERP calculated along
the fly, along with the dContactApprox1). My solid plain geoms when
dropped sit nice and still on the Plane.

However, my transforms (created, iirc, correctly) have a jitter. When
I built my robot up the jitter becomes more and more extreme.

I had less of this problem, or it was less noticable, when creating
large geoms. Most of the parts I'm making now are on the order of
50cms or so.

I've tried adjusting the global CFM/ERP and I haven't had much
success. I've added in BodyDampening and played around with those
values, also without much success. Additionally, increasing the step
size does help, but never fully correctly the problem.

I'm willing to live with some jitter, but I can't have my robots
blowing themselves apart after a while.

Any insight would be great. Excellent work with ODE in general, I do
not have a physics background, but I have been able to develop fairly
complex simulations -- kudos. If it is a problem with the
'squishiness' of the plane, how can I make it more solid? My kp is
already quite large.

Thanks for your time,


Other variables of interest:

Max contacts: 10
Step size: 0.002 .. 0.02
Kd = 0
Kp = Large (100000)
Dampening = -0.001

-- 
| Matt Stephure
| stephure at gmail.com
+----------------------------------------------------------