Volume Calculations on a sloped surface in 3d Map?

Dear Friends,
newbie here with WebODM but, since I discovered it, I’ve been “playing” with it a lot .
I am working on a Basalt Quarry project and they asked me to calculate their volumes.

Now, I was able to calculate their “flat” volumes in the way explained in the 2d Map; — by adding contours to the area and then the software automatically calculates them.
They seem pretty accurate.

But… since some volumes are on a sloped surface, what’s the best approach to define the base?

I went to the 3d MAP and there’s the “VOLUME MEASUREMENTS” under “Tools” / “Measuraments” tabs on the left. I like this as it’s possible to physically drow the area also on slopes. I can see the results under “Properties” but the results are different from the 2d calculations.

I tried to search in the forum for an answer , found this thread ( Issue in using measurement tools - WebODM - OpenDroneMap Community) which was very useful…
Any news about a guide, as was said there? or how to calculate on a sloping surface?

Could somebody help me out please? I would be super happy and grateful))

Wish you all a nice Sunday ,


The best way is still through the 2D map. When you click point on the map to make a volume measurement, each point defines the base. If you base is sloped, the calculation will reflect a sloped base. See the GRASS script that does this: WebODM/calc_volume.py at master · OpenDroneMap/WebODM · GitHub


As proposed by pierotofy, a triangulated surface is maybe your best shot.
If you have a DEM from a time before the stockpiles were formed, you can calculate volume differences in QGis, also you can try the Volume Calculation Tool for QGIS.


Thank you Guys, great info for a newbie!
Will study the matter more indepth.