The Default Origin is especially useful, if you want to rotate about two centers at the same time. When you set or animate parallel RotateA and RotateB channels together, you can create very interesting motion paths. However, you rarely need two rotation centers at the same time. And the Default Origin requires a specific default position of the prop geometry in the scene, since the center of rotation is based upon the center of the scene. Because of this, the Default Origin is not always helpful. You can use parallel channels to create a variable origin, that is, one animatable center of rotation. A property of a prop or actor is animatable (in Poser 4), if you can use a parameter dial (other than an "Origin" dial) to modify the property. Suppose you make a poseable railway model. The train should first rotate clockwise at radius R1, to move along a curve. The rotation center lies on the right at distance R1. Next, the train should rotate counter-clockwise at radius R2, to travel along the next curve. Now the rotation center is on the left at distance R2. The origin should be variable, to support different radii and rotation directions in course of the motion. If you try to modify the Poser Origin, the modified origin will always affect the entire animation (this is a static, non-animatable property). The train actors are not positioned at the center of the scene (and different wagons are at different default positions), therefore the additional Default Origin won't help. What you need is a variable origin, derived from the Poser Origin.