You compute volumes in the Volume tab of the Surface Settings dialog. This tab reports the slope areas based on the current slope ranges and allows you to edit the slope ranges as needed.
The computed cut and fill areas can be added to the current report view for publication. See Reports.
You can shade the cut and fill areas of a volume computation in different colors and hatchings in your drawing. This is a great tool when comparing two surfaces.
TPC uses a 'prism' method to compute volumes. This method is the most accurate possible method for volume computation using the TIN (triangulated irregular network) of each surface.
To compute the volume, TPC does the following: