To import a volume into the Volumes:
1. On the Menu bar, click View > Volumes.
2. On the sidebar, in the Objects section, click .
3. The Import Volume pop-up appears to navigate to the desired shapefile Volume_ToImport_surface.shp. It could be for example, a volume previously created with Pix4Dmapper of the same study area.
4. Select the file and click Open.
The volume is now imported and selected to be displayed in Volumes.
By default, the volume is called Volume 1 but it can be renamed by double clicking on the name and typing the new name.
Article feedback (for troubleshooting, post here instead)
When i import a surface created outside (or even edited in another bit of software), is there anyway to ensure it is draped to the DSM to give me the correct volume?
If I understood your question correctly, you can import a shapefile that has the same coordinate system and check the coordinates of points by looking at the right bottom of the Pix4Dmapper. You can also check visually by looking at the rayCloud.