[ODE] Values required to produce at least semi-realisticfrictionusing the default constant-force-limit model?

[John Miles]

As far as I can tell, ODE's friction value is used only to determine whether
or not something starts to move when gravity, or another force, acts upon it
(static or "starting" friction).  What you're asking for is dynamic
friction, which is the force that must be overcome to maintain steady motion
of one body in contact with another.

And I agree -- ODE should be handling this for us, ideally.  (Says the guy
with neither the math 'leetness nor the motivation to add it himself. :)

When someone runs the test_boxstack demo and sees spheres zooming losslessly
off into the distance at warp 9, their first conclusion is that ODE is lame
and broken.  Fortunately, I read the FAQ before I concluded that, but a lot
of people don't.  I imagine that a general implementation of dynamic
friction isn't as simple and generic as we're assuming it is, or Russ
would've already added it just to save himself the "This thing is full of
bugs" comments that show up every so often on the list.

-- jm

>
> I'm sure that would work, but if I'm going to be applying the
> friction force
> manually, I'm unclear what the purpose of ODE's friction value is, then?
>
> ... especially given how simple and generic that bit of code would be to
> apply to all bodies in the system, it seems surpising this isn't something
> ODE just handles?  I'd imagined that mu became something like the dragCoef
> in your equation below.
>
> -Megan Fox
>