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

[Megan Fox]

I did read the faq, but concluded that the manual friction mentioned there
was, as someone else said, something more for the emulation of air friction,
with surface friction already being taken care of.

... but anyways, to that end...

Can anyone describe how they've handled this in their engine?  For the
moment, I'm thinking the best solution might be to apply the drag
coefficient inside the collision callback (or further "inside" the engine if
possible, though I haven't looked at the internals yet) - grab the current
velocity of the objects and reduce them each by the average of the two
object's friction values, or somesuch thing?  Or maybe this isn't such a
great idea?

Thanks for any assitance in this,

-Megan Fox

> 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.