The Fill volume is the volume between the base and the terrain when the terrain is lower than the base. Thus, it indicates the material that has to be added in order to fill the area.
Unfortunately, it is not possible to directly edit the coordinates of the Manual Tie Points of the volume base in the Volumes tab. A workaround would be to enter the Manual Tie Points with their coordinates in the rayCloud, create a surface in the rayCloud based on those MTPs and export it as .shp and finally, import this surface in the Volumes tab and compute the volume area.
Another alternative for the case that you already have the volume is the following:
- In the Volumes view, draw your volume.
- Switch to the rayCloud view where you can only see the Manual Tie Points that are created after drawing the volume.
- Select the Manual Tie Point that you would like to move and adjust its position from the right sidebar where you see the images.
- Go back to the volumes view where you will see the new volume.
- Recalculate the volume.