[ODE] Degrees of freedom?

[Martin C. Martin]

A joint doesn't have any degrees of freedom.  Each body has six degrees of
freedom and a joint constrains (removes) some of the degrees of freedom of
the bodies it is attached to.  A ball and socket joint removes 3 degrees
of freedom, a hinge joint 5.

- Martin

> Henri Hakl wrote:
> 
> I've got a bit of a problem wrapping my mind around this, just set me
> straight where I go askew:
> 
> Each joint has potentially 9 degrees of freedom - some of which are
> restrained depending on the type of joint.
> 
> A hinge joint has ?? degrees of freedom.
> 
> A ball-and-socket joint has ?? degrees of freedom.
> 
> A ball-and-socket joint, combined with a motor joint (for axis limits),
> has the same degree of freedom as a standard ball-and-socket joint.
> 
> In an articulated system with seperate joints, the total degree of
> freedom is the sum of degree of freedoms in the individual joints.
> 
> Any problems? Thanks :)
>   Henri