i build a curve and want to change every point's normals by its two neighbor points. so the new normal will align the angular bisector of the angle between two edges of the point.
With a point() expression in a Point SOP you can query the position of the previous and next points. Create vectors pointing to both, normalize and add together.
(Apologies for the dot() in the .hip - my brain blanked on how to get one component of a vector
