Thank you for your reply. Before going any further, let me say what a great programme CloudCompare is and it has many applications for both surveying and mining.
It is not that I require the Z value for the meshes to be 0, but that that both meshes use the same minimum Z value when computing volumes. For example, if you have Mesh A, representing a stock pile surface, and Mesh B, representing the original ground below the stock pile, then the volume between Mesh A and B can be computed by calculating the volume of A from a defined minimum Z value plane, then calculating the volume of B, using the same minimum Z value plane. The difference between the two volumes is obviously the required net volume between A and B. However this is only true if meshes A and B cover the same Y,X areas.
I have checked example where the above two conditions hold true, and the resulting net volume from CloudCompare is very close to that obtained from our SURPAC Surveying Software.
However, as soon as I use and example where A and B have different minimum Z values, the resulting volume is way off. I am sending two simple .asc files (one representing the stock pile Surface and the other the original ground) directly to your personal e-mail. They cover the same surface (Y, X) area, but the Base model has Z values less than that of the Surface model. CloudCompare shows the two volumes as :-
Surface = 7,674 cubic metres
Base = 865 cubic metres
Diff = 6,809 cubic metres
the volume between these two surface models should be 10,597 cubic metres.
So what I am asking here is :-
Is it possible to get CloudCompare to search through two user defined (and loaded) meshes and determine the minimum Z value that occurs when looking in both files. Can the User then tell the Volume routine that, when computing the volume of each of the two defined Meshes, it must do so from this minimum Z value plane. I appreciate that this would only apply to "open" meshes (such as in this example) and not closed meshes.
The problem of one mesh covering a smaller area then the other can perhaps be looked at after the above query has been addressed.
Thank you and regards,