Recently I found the trimble scan essential plugin (Extension | SketchUp Extension Warehouse) for SketchUp. It has the ability to snap to imported point clouds, which is quite awesome. A video tutorial is on https://youtu.be/BZkFsNIkmPQ .
I know that we can build a custom tool and implement the snap function using InputPoint or PickHelper. However, how can we enable snap in native tool, such as PushPull, Rectangle, for point clouds? What is the entity behind for the Point Clouds?