# How to use btCompoundShape with btRaycastVehicle?

I use btBoxShape for creating a chassis btRigidBody. Then I define an initial position for the chassis rigid body, for example btVector3(0, 10, 0) and when animation starts a vehicle is dropped from that height. Everything works fine.

Now I wonder what is purpose for using btCompoundShape during creating a chassis rigid body and how should I set btTransform for btCompoundShape and a a chassis rigid body ?

When I just use btCompound shape with the following local transform (btVector3(0,1,0)) and a chassis rigid body has the transform as above (btVector(0,10,0)) I get following effect when vehicle is dropped: image