Compound shape rigid body doesn't collide, obey gravity, ..

[Yola]

I created compound shape rigid body. All other objects collide well, this one doesn't. But it falls through other objects due to gravity, strangely that other forces which i apply (tried ApplyCentralForce) doesn't affect it, but ApplyCentralImpulse affects it. What can it be? I use BulletSharp.

[bram]

Are you sure you added the body to the world with addRigidBody() call?

The sequence is:

- create btCompoundShape
- create child shapes, and add them with addChildShape()
- create btRigidBody with the compound shape as its shape.
- add the rigid body to your world.

[Yola]

I tried few things at home with bullet, so i tried to do the same at home with my C++ library. I do it like this:

Code: Select all

btVector3 boxDims(.5f, .5f, .5f);
auto compoundTransform = OrthogonalTransform::MakeTranslation(0, 5, 0);
auto compoundShape = make_unique<btCompoundShape>();
compoundShape->addChildShape(Tobt(compoundTransform), new btBoxShape(boxDims));
auto bodyCompound = CreateRigidBody(_dynamicsWorld.get(), compoundShape.get(), 5., Tobt(compoundTransform));

CreateRigidBody works for other types of rigid bodies. It adds to the world.

compound.gif

[Yola]

I believe i have found the error, i misused child transforms.