The physics transform to be used during the lifetime of the tween. When the PhysicsBody.TransformWriteTween.transformWriteMode is PhysicsBody.TransformWriteMode.Interpolate, this defines the target pose to move to. When the PhysicsBody.TransformWriteTween.transformWriteMode is PhysicsBody.TransformWriteMode.Extrapolate, this defines the source pose to move from.