Questions about measuring distances

[ahyslop]

I am trying to figure out whether cloud compare measures distances the way I want. I am trying to figure out the degree of roughness on a rock surface. I first developed a best-fit plane to the surface and then used C2M distances to measure how far the actual surface deviates from the plane.

I am looking for the orthogonal distance from the plane to the actual surface, is that was c2m computes?
I also want to export the histogram data that is output in the properties window, how do I do this?

[daniel]

Hi,

Yes, CC will compute the orthogonal distance as long as the projection of the point fall inside the plane boundaries (otherwise it will compute the distance to the nearest edge or vertex). So you may want to create a quite large plane if you want to be sure that it's always the 'projection' distance.

You can show the histogram with the 'Edit > Scalar fields > Show histogram' function. Then export the histogram itself as an image or a CSV file.

Another option is to export the cloud with the resulting distances as an ASCII file. This way you'll have all the distances (in a dedicated column) and you can compute the histogram 'your way'.

[WargodHernandez]

You can use cloud to primitive distance measurement with planes and choose to treat them as infinite planes. That will give orthogonal distance regardless of edges, without having to enlarge the plane.