btCollisionObject::CheckCollideWith() always returns true!

[EGD Eric]

Hi, I'm trying to use this engine to make a demo with physics, but I need to be able to detect when a collision happened between two rigid bodies. I tried checkCollideWith() function, but it always returns true, regardless of whether the two objects are actually colliding! One object is a rigid body that has a sphere as its shape, the other is a rigid body with a cylinder as its shape. All I do is:

Code: Select all

if(m_headbody->checkCollideWith( m_ballbody))
{
//collision!
}

Any advice? Maybe you prefer some other method that works for you? Any input would be appreciated.

[pico]

Bullet supplies no high level functions to check if bodies collided.
the function you use tests only if the collision filters of those two bodies match.

To see if two bodies have collided in the last physics step you need to iterate over the contact manifolds.
Check out the Wiki entry: http://www.bulletphysics.com/mediawiki- ... d_Triggers
"Contact Information" is what you are looking for.

[Dominik]

The way I check direct collisions between two distinct bodies

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btCollisionAlgorithm* pAlgorithm = pBtWorld->getDispatcher()->findAlgorithm( pBulletObj1, pBulletObj2 );
btManifoldResult oManifoldResult( pBulletObj1, pBulletObj2 );
pAlgorithm->processCollision( pBulletObj1, pBulletObj2, pBtWorld->getDispatchInfo(), &oManifoldResult );
btPersistentManifold* pManifold = oManifoldResult.getPersistentManifold();

However, I have no idea how good this approach is. In any case, he ignores the broad phase test, thus not being overly efficient