DESCRIPTION 
We now expand the previous exercise even further by creating a “Geometry Pipeline” that automatically reads all points on three separate layers, each with a different colour assigned. From this Point Cloud we find the closest three points only. We identify their associated colours, and use the distance to these points and their colour values to define the eventual mesh colouration. 

Note the use of the “index of closest point” parameter coming from the “closest points” button. This number defines for each mesh vertex the indices of the points in the point cloud that are closest to it. Since we have created a list of colour values as long as the list of points in the point cloud, we can use these indices to extract the correct colours associated with the closest points.