[ODE] how to glue bodies together ?

[Jeffrey Smith]

> I tried to use fixed joints but the results are unreliable 
> (as it's written in the latest doc). 
> I can workaround the problem, but I'd like to know if there's 
> a better way.

Use a "slider" constraint, with the high and low stops set to the same
value (i.e. the separation value you desire).  I've had good luck with
this workaround, and the resulting constraint is no more unstable
during collision, etc. than any other constraint.

-jeff