Hi,
I work with pointclouds all day - every day in Rhino.
What exactly are you trying to do ?
Yes, you are right, if you want to work with meshes instead of pointclouds, it is best to mesh them first in CloudCompare, using the “Poisson Recon” plugin .You can find documentation on the CloudCompare Wiki.
DO NOT try to explode the pointcloud ! it wll probably crash your computer every time
You can segment the pointcloud using the “Pointcloud” command and using the add/remove options.
It can take time but it works very well, especially if you also include the “Lasso” command to select points.
You can export a pointcloud out of Rhino as a .PLY file, then convert that back to an E.57 using CloudCompare.
You can import a mesh into Rhino then convert it to a Quadmesh, then to a Subd object but my workflow is to generate polylines from the pointcloud then loft etc those to create surfaces.
Dont give up, with a bit of persistance and practice you can create any model from a scan with Rhino 7.
If you are going to do this a lot it is really worth learning all the CloudCompare functions, it is a really powerful software package.
More discussion Here - Reverse engineering: convert mesh to nurbes - #15 by hanscad
Regards,
Mike.