Problems with internal types / collision masks

2014-05-25T18:28:59+00:00

Hallo im new to bullet so my problem may be my current understanding of bit-masks in bullet.

The Problem:
I created a class, btFractureBody, which inherits from the btRigidbody class and defines a mask for these kind of rigidbodys as internal type.

Code:

[btFractureBody]#define CUSTOM_FRACTURE_TYPE (btRigidBody::CO_USER_TYPE | btRigidBody::CO_RIGID_BODY | btRigidBody::CO_COLLISION_OBJECT)

When a btFractureBody is initialized i set the internal type to my custom mask.

Code:

[btFractureBody]btFractureBody(const btRigidBodyConstructionInfo& constructionInfo, btDynamicsWorld* world):btRigidBody(constructionInfo),m_world(world),m_principalAxis(btTransform::getIdentity()){m_masses.push_back(constructionInfo.m_mass);m_internalType  = m_internalType | CUSTOM_FRACTURE_TYPE;m_collisionFlags = m_collisionFlags | CollisionFlags::CF_CUSTOM_MATERIAL_CALLBACK;}

in the same class (btFractureBody) i have added a static collision callback method which i set to be a a in the demo.

Code:

[btFractureBody]bool btFractureBody::collisionCallback(btManifoldPoint& cp,const btCollisionObject* colObj0,int partId0,int index0,const btCollisionObject* colObj1,int partId1,int index1){bool isFractureObject0 = (colObj0->getInternalType() & CUSTOM_FRACTURE_TYPE) == CUSTOM_FRACTURE_TYPE;bool isFractureObject1 = (colObj1->getInternalType() & CUSTOM_FRACTURE_TYPE) == CUSTOM_FRACTURE_TYPE;if(isFractureObject0 || isFractureObject1)printf("obj0: %d idx0: %d\nobj1: %d idx1: %d\n\n", isFractureObject0, index0, isFractureObject1, index1);if(isFractureObject0 && cp.m_appliedImpulse > BREAK_THRESHOLD){btFractureBody* fb = (btFractureBody*)upcast(colObj0);btScalar radius = cp.m_appliedImpulse/20.f;btVector3 hitPos= cp.getPositionWorldOnA();btCompoundShape* compoundShape = (btCompoundShape*)colObj0->getCollisionShape();int size = compoundShape->getNumChildShapes();                printf("num childs: %d\n", size);for(int i=1; igetChildTransform(i).getOrigin()-hitPos).length2() < pow(radius,2) )fb->removeChildBodyByIndex(i);}fb->shiftToCenterOfMass();}return false;}[Demo:initPhysics]gContactAddedCallback = (ContactAddedCallback)btFractureBody::collisionCallback;

The programm prints for the number of childeren unrealistic values e.g. minus values, which indicates that given collision object does not contain a compound shape, but every btFracturBody must contains a compound shape, only childs are added.

The collision callback as it is does not work, can you tell me why, every kind of advice is appriciated, thanks.

Statistics: Posted by EruFeanor — Sun May 25, 2014 6:28 pm

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Problems with internal types / collision masks