Setting Position of Bullet Affected Nodes

[Dark Dragon DX]

Not sure if anyone else has something like this, but I figured it can help. (Probably very inefficient, but its the only way I know.)

Code: Select all

World->removeCollisionObject(Body, false);
Node->setPosition(position);
IRigidBox *Body = World->addRigidBody(Shape);

IRigidBox can be changed to any other body type.
Body is the body affecting Node.
Node is the pointer to an ISceneNode.
World is obviously a pointer to IrrBulletWorld.

Yea, I know this is an incredibally simple snippet, but this caused me quite a few problems not knowing about the removeCollisionObject command. So I figured this could be useful to other people that didn't know it was there either. It also works with setRotation and setScale.

[hayate]

Code: Select all

World->removeCollisionObject(Body, false);
Node->setPosition(position);
IRigidBox *Body = World->addRigidBody(Shape);

IRigidBox can be changed to any other body type.
Body is the body affecting Node.
Node is the pointer to an ISceneNode.
World is obviously a pointer to IrrBulletWorld.

Hi, what is "Shape" in "World->addRigidBody(Shape);" Is it the mesh of Node?

[shadowslair]

Hi, what is "Shape" in "World->addRigidBody(Shape);" Is it the mesh of Node?

The shape is the collision representation of the body. For example you wanna create a football ball- the shape is a sphere with some radius and the body holds the transformation, mass etc. physics` properties. Sth like that. You can have a shape that uses the node mesh to be build. Depends on what library you use and the thing you need to use it for.

[cobra]

Dark Dragon DX:

If you're doing this when you "spawn" a new object, that's fine, and the correct way to do it, because the IRigidBody constructor automatically sets its transformation to the scene node's transformation.

However, because you first remove the object and then create a new one at the new position, it seems like you're simply trying to re-position the object.

To do this, use ICollisionObject::setWorldTransform() and give it a matrix4 that describes the new transformation.

- Josiah

[Dark Dragon DX]

Dark Dragon DX:

If you're doing this when you "spawn" a new object, that's fine, and the correct way to do it, because the IRigidBody constructor automatically sets its transformation to the scene node's transformation.

However, because you first remove the object and then create a new one at the new position, it seems like you're simply trying to re-position the object.

To do this, use ICollisionObject::setWorldTransform() and give it a matrix4 that describes the new transformation.

- Josiah

Oh, thanks. I'm relatively new to the engine so I'll have to learn how to use matrix4. (Sorry for epic long post delay, I'm never on the forums)