RMS

[ksheen]

Hello,

I am learning how to use CloudCompare software and I have some doubts. For my research, I am comparing two 3D models of footwear. I registrate the model with the option of matching points,then ICP the 2 models and compute the cloud points distance. The RMS given was 0,00345 , mean distance 0,00346 and stdesv 0.00435. My questions are: the mean distance mean: 0,00346 mm, RMS mean : 0.00345 mm?, I am not sure because the numbers are really low , so I am dont know if I am doing something wrong.

Thanks

[daniel]

Yes, the numbers are really small. But what are the units?

And the fact that the average is very close to the std. dev. (or the RMS) is maybe by pure chance. But you can visually look at the distribution of distances, or by looking at the histogram.

[ksheen]

Hi
when I created the 3D model, the scale was in milimeters, so I guess the units used for mean distance and stdev given by Cloudcompare are in milimeters too, correct?

[ksheen]

Also I don't know if I can change the units in Cloudcompare

[daniel]

Yes all distances and measures are reported in the same units as the original coordinates.

You can change the scale by using the 'Edit > Multiply/Scale' method (it will multiply all the coordinates by a factor).