[ODE] Breakable joints

[Amund Børsand]

Roel van Dijk <roelvandijk@home.nl> skreiv:

> I thought it would be nice to have breakable joints in ode. You can do realy 
> cool things with breakable joints. For instance a tank that looses it's 
> turret when it is hit or (for the sadistic) bipeds that can loose limbs.
> It is real easy to implement. 

Great idea! I've thought of something similar as well, but never gotten
as far as implementing it (or pondering how to). Would it be possible to
implement bending as well? It would be cool to have a car sim that acts
so that if you land too hard on one wheel at an angle, it gets bent, or
breaks off if the forces are bigger. Bending means something like
rotating the initial joint setting I guess, or just rotating the geom a
little in relation to the joint, and in response to the forces it
recieved.

It would also be cool to snap axleshafts in my rockcrawler, I've thought
of that as well.. well, that's doesn't really have anything to do with
your code, it just means that if a wheel gets "overloaded" (real axle
shafts have a rating for how much torque they can take), the wheel wont
propel the car anymore. With realistic input data, it could be quite a
realistic simulation.