CloudCompare forum

How can I select and area (like an excavated area), and calculate volume difference between two pointclouds ?

It depends on the cloud shape, but I guess you could first use the 'scissors' tool (see http://www.cloudcompare.org/doc/wiki/in ... ation_Tool) to segment the point inside the right area, and then the '2.5D Volume calculation' tool to estimate the volume (see http://www.cloudcompare.org/doc/wiki/in ... .5D_Volume).

You may also have to transform the clouds so that they are roughly 'horizontal' in order to get a better estimation of the volume.

Thank you
In the mean time I used "cross section" tool to shrink the area (while both pointclouds were selected) and copy as new selection, then compared the selections. , then the 2.5D volume calculation
apparently, that worked fine.

Thanks for the links, scissors sound like a even better way.