CloudCompare forum

Hi all,

I am new to Cloudcompare and I did my best to google previous answers to my problem, so sorry if it is a bit noobish.
I have a Point Cloud of a building and I need to create straight planes of walls and the roof. When I use the "Point List Picking" command and select 4 points, the "Fit/Plane" command doesn't do anything. Am i doing something wrong?

I select the 4 points from the "DB tree" before doing the "Fit/Plane" command. The 4 points are just the corners of a straight wall, it isn't a complicated shape at all. When I select the whole point cloud house, the "Fit/Plane" does work (but it gives some weird plane plane). The function does work but I don't know what I am doing wrong.

Hope someone can help

I believe the 'Fit plane' method requires more than 4 points to work (as we use a Least Squares fitting algorithm and it would be weird to use it on so few points).

Anyway to get more points on your planes, you should first segment the cloud in various parts. You can use the scissors tool to do this (http://www.cloudcompare.org/doc/wiki/in ... ation_Tool) for instance. Once you get the various walls as independent clouds you should be able to use the 'Fit > Plane' method.

You could also play with the qRansacSD (Ransac Shape Detection) plugin. You can tell it to automatically detect planes only. Sometimes it can be a time saver for this kind of process.

Thank you very much Daniel,

it worked!

Hi Daniel,

Is the ransackSD already integrated into Cloudcompare, or does it need to be added separately? If separately, is there a documentation/tutorial that provides help in doing this?

It's shipped with the Windows version by default (I'm not sure about the other OSes ;).

http://www.cloudcompare.org/doc/wiki/in ... n_(plugin)