Bullet world space coordinate system is the same as opengl world coordinate system. I have noticed that raycast vehicle has the following function:

virtual void btRaycastVehicle::setCoordinateSystem(int rightIndex,
                                                   int upIndex,
                                                   int forwardIndex) 

How does that function work ?

By default raycast vehicle has the following parametets:

  • forward vector: [0, 1, 0]
  • forward axis: 1
  • right axis: 0
  • up axis: 2

Does it mean that y axis is swapped with z axis ?

After calling:


I get the following parameters:

  • forward vector: [0, 0, 1]
  • forward axis: 2
  • right axis: 0
  • up axis: 1

which makes more sense to me but I'm still confused why a default setup is other (not compatible with world coordinate system) and how to interpret it.


1 Answer 1


this is Left-hand Rule or Right-hand Rule, that will Affects the direction of the rigid body, you can set value to try.


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