[ODE] I'm confused....

[Eric Trousset]

> -----Message d'origine-----
> De : whitt013 [mailto:whitt013@bama.ua.edu]
> Envoyé : mercredi 5 mars 2003 06:38
> À : ode@q12.org
> Objet : [ODE] I'm confused....
> 
> 
> I've been playing with dJointFeedback, trying to get breaking 
> joints to 
> working somewhat realistically, and I noticed something odd.  
> The amount of 
> force a hinge exerts on body 1 is roughly negative (usually 
> exactly) of what 
> it exerts on body 2.  However, the amount of torque it exerts 
> on each body is 
> nowhere near.... Shouldn't a joint exert equal torques in 
> opposite direction 
> (especially in freefall)?  Isn't that one of Newton's laws?  
> Or is this one of 
> the inaccuracies of ODE?  Or am I dumber than I thought in 
> the world of 
> physics?
> 
> So what would make the best measure of whether this joint has 
> taken "too much 
> stress"?  I was thinking something along the lines of the 
> magnitude of the 
> torque vector, but now kind of wonder about that... and which 
> one to use.  Any 
> input would be helpful.

I think you should use the torque or the force depending of the joint; 
you should use the torque and the force depending of wich DOF is disable 
by the joint. For example, a ball disable 3 translating dof, so, you could 
use the force magnitude around this dof.

> 
> Thanks,
> David Whittaker
> 
> 
> _______________________________________________
> ODE mailing list
> ODE@q12.org
> http://q12.org/mailman/listinfo/ode
>