[ODE] exploding spinning objects

[Erin Catto]

I suggest creating a long skinny box, and set it rotating at a high angular
velocity about a random axis. You might to need have some collision with
ground to get transfer to linear momentum. If it is unstable it should have
it's energy increase significantly:

E = 1/2 m * v^2 + 1/2 omega * I * omega + m * g * h 

Erin

-----Original Message-----
From: J. Perkins [mailto:starkos at gmail.com] 
Sent: Tuesday, February 14, 2006 4:55 AM
To: Nagymathe Denes
Cc: Graham Fyffe; Erin Catto; ode at q12.org
Subject: Re: [ODE] exploding spinning objects

On 2/14/06, Nagymathe Denes <denes at invictus.hu> wrote:
> Thanks for the info. But if this term would work correctly even for 
> spheres, the well-known problem of 'wheels losing alignment' wouldn't
exist.

Do we know what is causing this term to make the simulation unstable?
Is it numerical instabilities? I spent a few minutes with the latest
unstable source code trying to reproduce the problem with no success.
If someone would be so kind as to send me a source code sample that blows
up, I'll wrap it up as a unit test so we can start investigating.

Thanks!

Jason