[ODE] Box on The Ground

[paul.bridger]

I think this is the problem I just had. I had something travelling at 1000
length/time hitting something stationary. The collision was very violent and
unstable. Making everything smaller and speeds correspondingly so made
everything very good.

Perhaps your using millimetres as your unit is causing a similar problem?


A related question: can anyone give me an impression of how much more
efficient ODE will be with single precision cf. double precision?

Liu Wei-Wen wrote:

> I create a ground (0, 0, 1) and create a Box (1000mm*1000mm).
> I set the gravity is -9810mm/s/s.
> and set
>  
>     dJointID c;
>     dBodyID b1 = dGeomGetBody(o1);
>     dBodyID b2 = dGeomGetBody(o2);
>     if (b1 && b2 && dAreConnected (b1,b2)) return;
> 
>     dContact contact;
> 
>     contact.surface.mode = dContactApprox1_1 | dContactApprox1_2 |
>                                           dContactSlip1 | dContactSlip2 |
>                                           dContactSoftERP | dContactSoftCFM;
>     contact.surface.mu = dInfinity;
>     contact.surface.mu2 = dInfinity;
>     contact.surface.slip1 = 0.0;
>     contact.surface.slip2 = 0.0;
>     contact.surface.soft_erp = 0.8;
>     contact.surface.soft_cfm = 1e-10;
> 
>     if (dCollide (o1, o2, 1, &contact.geom, sizeof(dContactGeom)))
>     {
>         c = dJointCreateContact (robot->worldID, robot->ContactGroupID, 
> &contact);
>         dJointAttach (c, b1, b2);
>     }
>  
> but when i put the box on the ground, the box will jump always.
> thanks a lot.
> 
> 
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