I apologize for my limited understanding on this topic.
I am currently trying to measure surface roughness and have been inputting random values into the "local neighborhood radius" box. This has resulted in different roughness values, as shown in the attached images.
Could you please clarify the appropriate value for the roughness parameter? and most importantly, what is the unit of the roughness parameter
Could you please clarify if the value in the "local neighborhood radius" box serves as the reference or base surface for comparison?
Additionally, what is the unit of roughness measurement—is it in millimeters, or is it simply an indicator?
Apologies for my basic questions; I’m working on measuring surface roughness (or surface parameters) for a fatigue study
The radius is simply the radius of a sphere around each point where we look for the neighbors. The larger the radius, the more points will fall inside. Which will then make the fitted plane less impacted by local noise for instance, or by the local roughness of the surface, but on the other hand it might be impacted by the fact that the shape is not flat, and there will be a bias. And conversely, a small radius will be very sensitive to noise (if any) but the planar fit will likely be more meaningful.
And the result is a distance. So it's the same units as your cloud (CloudCompare doesn't know which unit your cloud is expressed in, as it's not an information that's present in most of the file formats - it simply loads the coordinates as they are from the file). You can use the point picking tool to measure the distance between 2 points for which you know the real distance, or use the scale bar in the bottom right part of the screen as a reference.