[ODE] Problem with missing friction

Arturo Colorado Garín acolorado at telefonica.net
Tue Sep 5 11:54:27 MST 2006

> I used this flag already and it changed nothing on the effect that the
> velocity
> got ignored. The mass is also set to 1.0 to avoid start errors. So
> concerning
> the values things should be alright yet only the forces added before the
> simulation step is used but not the velocity. I can set velocity always to
> 0 and
> apply the velocity as force but I suspect this to mess up the simulation.

Hmmm... Is your floor what is moving (a kind of moving platform), by any
chance? If so, I assume the floor is a bodyless geom and you're moving it by
setting its position manually before each step. I just made a quick&dirty
test in my game with this scenario and I got the same result: no friction at
all between the moving platform and the box standing on it.

It does make sense, a geom by itself doesn't have any physical property so
ODE has no way to tell what is its velocity, and thus no friction will be
generated at all. In this case, the dContactMotion1 flag in the contact
joint looks like the solution to this situation (haven't tried yet though).

Here is a direct link to the contact joint documentation:

Please, let us know if this is your scenario or not.


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