No subject

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9.7.3. Plane class

dGeomID dCreatePlane (dSpaceID space,
                      dReal a, dReal b, dReal c, dReal d);

Create a plane geom of the given parameters, and return its ID. If space
is nonzero, insert it into that space. The plane equation is
    a*x+b*y+c*z = d
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It's not a bug.

David

> Thanks for the replies, people.  Its good to find such a helpful
> usergroup.
>
> to David McClurg:
> 2. I am applying both a force for velocity damping and a torque for
> rolling resistance, though right now I´m more interested in the former.
> I´ve tried just the velocity damping, a combination of both, total
> damping ( coefficients of -1.0 for both ), your constant force method,
> but nothing helps me to bring my objects to a quick stop except
> paradoxically reducing their mass.   Thanks for your pragmatic method,
> with tweaking it worked for me but I´m hesitating to use it for the
> sensitivity of the friction parameter to body velocity...  Instead I´m
> just leaving it as force applied based on a high (-0.9)  coefficient of
> the linear velocity.
>
> to david at csworkbench.com:
> 2. Drag.  I have now experimented with various flags in the contact mode
> parameter.  From the beginning I had the dContactApprox1 flag included,
> so thats not the problem, unless another flag is interfering.  But
> trying to remove other so far flags retains this behaviour, ie that the
> time taken to slide to a stop increases with extra density...  Anyway
> any illumination you give on how combining these flags and their
> parameters can effect contact response is very welcome. One thing you
> mentioned in your later elaboration of drag and friction is that you´d
> apply the former after collision detection but before the step.  I´m
> doing this after the step, but I´m not sure if that might be
> significant.  It seems that the constraints entailed by the contact join
> generate the forces/torques during the step....  si it doesn´t matter if
> I try to intervene before or after. The problem is probably as you
> suggested originally that I´m generating the wring sort of contact
> joints.
>
> Btw regarding aerodynamic drag, I´d love to see that implimented.   The
> moment that really convinced me how important good dynamics could be was
> watching Karl Sims swimming creatures evolve to use their limbs as
> paddles :)=
>
> 3. I´ve added bounding planes as per your suggestion.  Duh!  One curious
> thing though: I use the standard ax+bx+cx+d=0 equation for my planes,
> but I found I had to negate d when passing the plane to ode for the
> collision to work correctly ( at least with dCollideSpherePlane ).  Does
> Ode use ax+bx+cx-d=0 or is that a bug?
>
>
>
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