Pick points with mouse drawing a polyline

[marcodc-sys]

Hi there,
I am working on an industrial project based on acquiring the 3d point cloud of an unknown object with a laser scanner technology.
Once the object has been acquired the user has to select a specific area on the point cloud (e.g., drawing a polyline with a mouse) because a robot has to perform some tasks (e.g., painting) on that area.
I am wondering if it is possible with open3d to pick points inside a polyline drawn by the user using the mouse and for example storing them inside numpy array.
I cannot find any examples available so I need some help.
Thanks a lot