Getting list of triangles involved in collision.

[Rademanc]

Hi there.
I have a thorny problem.
I have a wall(triangle mesh) and I need to figure out which parts of the wall have been colliding with a cone. Is there a way to retrieve a list of the triangles that are colliding with the Cone?
Is there another way to do this?

[smallping]

Hi, I have the same problem. Does Bullet support this or not?
I found in the manual, a callback function

virtual btScalar btCollisionWorld::ContactResultCallback::addSingleResult ( btManifoldPoint & cp,
const btCollisionObject * colObj0,
int partId0,
int index0,
const btCollisionObject * colObj1,
int partId1,
int index1
)

In this function, the index0 and index1 is the index of colliding triangles, or not?

[Erwin Coumans]

Yes you can use a callback to find the actual triangle (and part) index.

The index and partId points to the triangle index and (optional) part of a triangle mesh, in case you are using btBvhTriangleMeshShape.

Note that it is best to use Bullet-2.81, the interface changed slightly:

Code: Select all

static bool ContactAddedCallback(btManifoldPoint& cp,	const btCollisionObjectWrapper* colObj0Wrap,int partId0,int index0,const btCollisionObjectWrapper* colObj1Wrap,int partId1,int index1);