Create Volume Under Surface
The Create Volume Under Surface option allows you to generate a volume under a selected surface. To use this option:
- Select the Geometry
workflow tab.
- Select a Surface Geometry entity in the model view or the Visibility Tree. Only ONE surface entity can be selected.
![selected surface](https://static.rocscience.cloud/assets/help/roctunnel3/figures/create-vol-fig-1.png)
- Select Geometry > Surface Triangulation Tools > Create Volume Under Surface
![Create External From Surface](https://static.rocscience.cloud/assets/help/roctunnel3/figures/create-volume-under-surface1.png)
- In the dialog, enter the desired Bottom Elevation (z coordinate) for the bottom of the volume or the Depth from Surface.
- Click OK to generate the volume from the selected surface.
![Example Geometry Created from Surface](https://static.rocscience.cloud/assets/help/roctunnel3/figures/create-vol-fig-2.png)