This node allows you to store the difference between the transform on a given point on the first input to a corresponding point on the second input - these inputs can be two topologically similar skeletons or two completely different skeletons that have been mapped using the Map Points SOP.

The difference can be computed between world or local transforms, or any custom Matrix attribute that is present on both inputs (a rest_transform attribute, for example). You also have the option to store the difference between animated inputs on a given frame, or on the current frame of the animation. For example, if we have a t-pose on frame 1 of an imported animation then we can just compute the offset using that frame, however we could use the latter approach to compute the local space delta for an animated skeleton from a given 'rest' position that we specify on the second input.

{
    'reference': string, // The point attribute on the driver skeleton to use as reference. If set to "ptnum", the point number will be used.
    'value': string or int // The value of the point attribute on the point to use as the driver.
}