[ODE] Joint friction (the previous mail is lost?)

[Remi Ricard]

Hi,

> 
> I sent the original mail three days ago and did not
> see it go through. Here is the second trial. 
> 
> I create a Hinge joint between two bodies(composed of
> Mesh Gemo), and use dJointAddHingeTorque to apply
> torques to the joint. I have to assert a unreasonable
> large torque (compare to body mass) to be able to move
> the bodies. Is it the friction effect? 
> why is the friction so big? How can I remove the
> friction effect? I have eliminated gravity effects. 

Ode does not introduce any friction in a joint.
I have several demos where the oscillation in a joint will keep going 
for ever if I don't stop it.

Ex
          To world (i.e. body == NULL)
              |
              |                      |
              |                      | Gravity
                                     V
       Hinge Joint Pointing out
               \
                \
                 \
               Ode body

Create the above example and
Release the Ode body and it will swing for ever.


The problem could be you have limits on the Hinge joint and you try to 
overcome those limits. The force at the limits is usually infinite.


Remi