Compound Objects: Get colliding child-shape's userdata.

2013-11-29T14:22:07+00:00

Hi All,

I have a compound shape with a bunch of child shapes, for each child-shape I also attach a small user data object containing some specific data for that child shape.

As an (simplified..) example , imagine a compound shape made out of 4 tiles. Each tiles has some user data value giving a certain amount of points:

Code:

------------------------------|             ||             |     | userData{4} || userData{1} ||             ||             |--------------++-----------------------------++---------------|             ||             |     | userData{5} || userData{7} ||             ||             |-------------------------------

And per frame I check the dispatchers manifolds whether something is colliding with 1 or more of the tiles.
At the moment, say a ball, collides with 1 of the subshapes of the compound shape I need to get the userdata of that child-shape.

Q: how do I get that child-shape user data back from the collision manifolds?

ie:

Code:

int numManifolds = m_collisionWorld->getDispatcher()->getNumManifolds();    for (int i=0;igetDispatcher()->getManifoldByIndexInternal(i);      int numContacts = contactManifold->getNumContacts();      btCollisionObject* object_A = static_cast(contactManifold->getBody0());      // somehow get the childshape making the actual collision      // get userdata from childshape.      // do stuff with userdata    }

edit: While it might be obvious for some readers that it would be easier to simply create 4 completely seperate boxes instead of a compound shape of boxes, for my application that won't fly sadly.

Statistics: Posted by Karrok — Fri Nov 29, 2013 2:22 pm

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Compound Objects: Get colliding child-shape's userdata.