[ODE] trimesh vs plane

[Bram Stolk]

Jean-Sebastien Guay wrote:

> - In test_trimesh, the trimeshes collide well between them but fall straight
>   through the floor while primitives collide with the trimeshes and the floor.

This is because the plane-trimesh isect is not implemented in ode.
These are currently implemented:

(dSphereClass,dSphereClass,&dCollideSphereSphere);
(dSphereClass,dBoxClass,&dCollideSphereBox);
(dSphereClass,dPlaneClass,&dCollideSpherePlane);
(dBoxClass,dBoxClass,&dCollideBoxBox);
(dBoxClass,dPlaneClass,&dCollideBoxPlane);
(dCapsuleClass,dSphereClass,&dCollideCapsuleSphere);
(dCapsuleClass,dBoxClass,&dCollideCapsuleBox);
(dCapsuleClass,dCapsuleClass,&dCollideCapsuleCapsule);
(dCapsuleClass,dPlaneClass,&dCollideCapsulePlane);
(dRayClass,dSphereClass,&dCollideRaySphere);
(dRayClass,dBoxClass,&dCollideRayBox);
(dRayClass,dCapsuleClass,&dCollideRayCapsule);
(dRayClass,dPlaneClass,&dCollideRayPlane);
(dTriMeshClass,dSphereClass,&dCollideSTL);
(dTriMeshClass,dBoxClass,&dCollideBTL);
(dTriMeshClass,dRayClass,&dCollideRTL);
(dTriMeshClass,dTriMeshClass,&dCollideTTL);
(dTriMeshClass,dCapsuleClass,&dCollideCCTL);
(dCylinderClass,dTriMeshClass,&dCollideCylinderTrimesh);
(dCylinderClass,dBoxClass,&dCollideCylinderBox);
(dCylinderClass,dSphereClass,&dCollideCylinderSphere);
(dCylinderClass,dPlaneClass,&dCollideCylinderPlane);

cyl-cyl, also missing, is a hard problem, but trimesh-plane should
not be too difficult to implement, as it is an easier problem than
trimesh-trimesh.

   Bram