CloudCompare forum

Dear Daneil

I would like to know which mathematical formula is used in the diagram to calculate the roughness index.

Thanks

No real formula, but the computation of the best fit plane on the points neighbors (see https://www.cloudcompare.org/doc/wiki/i ... =Roughness).

It looks like you have a few questions about the roughness calculation. I know you have written out a description of how it is calculated but would this formula be an accurate representation of your description?

Rj=(|ΔZ1|+|ΔZ2|…|ΔZi |)/n

where R is roughness calculated for points within a kernel radius of j, 𝛥Z is the difference in elevation from a measurement point and the least squares plane calculated by the nearest neighboring measurement points and n is the number of measurement points within a kernel radius.

Actually the roughness value for a single point is directly (and only) the distance from this point to the best fitting plane. There's no sum or average.