Whenever Poser updates the scene, the channels are evaluated according to the script execution order. When you experiment a little bit with the channel order, you can figure out how the offset channels work. When Poser starts executing the channels of a prop or actor, the center of rotation is assumed to be at x=0, y=0, z=0. This means: The channel evaluation always starts with an origin at the center of the scene. In the arrow example, the origin is first at the bottom end of the arrow, which is placed at the center of the scene. When the OffsetA channels are executed, the center of rotation is set to the origin coordinates, which are stored in the OffsetA channels (step 1). Poser uses the OffsetA channels to activate the origin of the prop or actor. In this example, Poser puts the center of rotation to the top of the arrow (the origin coordinates x=0, y=1, z=0). Next, Poser evaluates the Rotate channels one after the other (step 2). The order of the Rotate channels defines the so called "Rotation Order" (a very descriptive term, as you can see). The Rotation Order is only important, if more than one Rotate channel is set (not zero). The Rotation Order defines the gimbal lock behavior of the object, when several Rotate channels are set. In this example, the zRotate channel is set, so that the arrow prop rotates about the z axis, the center of rotation at the upper end. Next, the OffsetB channels are evaluated (step 3). These channels store the negative values of the origin coordinates. When the OffsetB values are added to the OffsetA values, the result is x=0, y=0, z=0. Poser seems to use the OffsetB channels to reset the previous origin (that is the center of the scene). When the last channel has been executed, Poser updates the scene and renders the new position and orientation of the prop. The moving origin and the evaluation of single channels are invisible to the user. Because of this, you can do virtually anything you like during the script execution. Only the final position and orientation of the model will be drawn to the screen.