Roughness of a surface

[Loic3913]

Hello CC community,

I'm working with scans of a snow surface (about 200 m2 and 8 millions points/scan), my goal is to study and quantify the surface roughness. The surface scanned has a certain slope so I would need to detrend the data to keep only the surface variations.

I tried to use the tool Roughness where "the 'roughness' value is equal to the distance between this point and the best fitting plane computed on its nearest neighbours", with a radius up to 0.2 m (above CC was not responding), however I'm not sure to understand if this tool is suitable for my needs.
I didn't find more documentation on this tool than the citation above. Is it working with a high pass filter ?

Thank for your help

[daniel]

You only have 8 million points and CC is not responding with a radius > 0.2? (are your cloud units in meter?). That's really surprising, but that's unrelated to your question ;). Still, I would be interested by an example file if you can share it with me (daniel.girardeau [at] gmail.com).

Then, the Roughness tool is independent on the slope (as it fits a local plane) which is probably good in your case. Otherwise the computation is as simple as you described...

[Loic3913]

finally it's working with a radius > 0.2 (meter), but it's a bit longer, thanks anyway