Not sure if I named this post clear enough. However, I have primitive with 4 points. I want/need, using VOP (if possible) to calculate distance between specific points. Want to calculate vector between point 0 and 1, and also between 0 and 3, for example. I was trying to use compare and if operators, so I filter needed points but I can not get correct values. I am guessing that VOP is doing operation per point so I can not access all points on one iteration, correct?

What would be best approach for this?

Use an Import Attribute vop with a Constant plugged into ptnum. If you don't have the Constant as an input it will grab global ptnum.

Thanks that is exactly what I needed! In mean time I solved it with PythonSOP.