Picking actors

I met spent a couple of hours on this picking problem.

Problem:

My pointPicker is giving strange values. Values that are obviously greater than the number of points I have.

Solution:

I had more than one actor in my Render Window Interactor, and the picker was accessing them.

All I had to do was

myActor.PickableOff()

This made my other actors unpickable, so that the picker could do its job of picking my main actor.