The start rotation of the tween. When the _transformWriteMode is PhysicsBody.TransformWriteMode.Current, this is set to the last _rotation but is not used. When the _transformWriteMode is PhysicsBody.TransformWriteMode.Interpolate, this is set to the last _rotation. When the _transformWriteMode is PhysicsBody.TransformWriteMode.Extrapolate, this will be calculated from _physicsTransform. See _rotation.

public Quaternion rotationFrom { readonly get; set; }