Transforms are written but the rotation is converted to a Quaternion where only a single axis is written, all others will be set to zero rotation. This is the fastest method of writing transforms however, any 3D rotations or rotations on the unused axis will be reset to zero. The rotational axis written to depends on the current PhysicsWorld.TransformPlane selected with _transformPlane where it will always be perpendicular to the transform plane.

Fast2D = 1