Models "BCAtan22.cr2" and "BCPolyAtnInk.cr2" use two different methods to adjust the pitch and yaw orientations. The pitch orientation is a rotation angle "alpha" which sets the zRot channel of actor "dummy". This is the method used for both angles in the simple code variant. To adjust the yaw orientation, models "BCAtan22.cr2" and "BCPolyAtnInk.cr2" implement a non standard IK-chain which serves as a special constrain operator: When you translate the goal of an IK-chain, the upper links are re-oriented because they follow the movement of the goal. Children of an upper link, which are not part of the IK-chain, are also re-oriented because they follow the movement of their parent. When you establish an IK-chain from the tip of the index finger (goal) to the forearm, and then move the goal, the hand and all fingers will be re-oriented. Because of this, the IK-chain can be (ab)used to constrain a branch of the hierarchy to a target. You cannot do the same with the PointAt command. The model has an additional actor "tangent". "tangent" is translated to the coordinates of the second Bezier curve (points "T") and moves on the second curve. "tangent" is the goal of a very short IK-chain. When "tangent" is translated, the upper link "pivot" rotates and child "dummy" follows the rotation of its parent. Therefore, "dummy" and all children of "dummy" will be re-oriented automatically, i.e. point in the direction of "tangent". For several reasons the standard IK-chain doesn't work in this example. I used a non standard 2-bones variant. As you can see in the picture, the inkyParent of the last link (actor "tangent") is "pivot" (instead of "BODY"). This makes the IK-solver of Poser a little bit nervous at times, but the model works quite well. If you try out model "BCPolyAtnInk.cr2" or "BCAtan22.cr2", be sure to parent your object to actor "dummy". When you scale the parented object, Poser sometimes rotates the object. This effect seems to be a conflict in the evaluation order due to the incomplete IK-chain. You can sometimes see a similar effect when you deactivate a standard IK-chain. To clean up the scene, move the "Plot" master channel a little bit, then reset all rotate channels of actor "dummy" and of your object (or root actor) to zero, then rotate your object if necessary.