Cut and Fill Problems.

[beegee]

( Using 8.0 20050620_2300 )

Case A:

Create a topo surface in the Existing Phase.
Split the surface. ( Create a topo surface within the boundaries of the original, still in Existing phase )
Grade the topo surface ( within the original boundaries , using "Copy Internal Points ")
Note that no Cut and Fill Volumes are reported in the properties of the graded surface.
Case B:

Create a topo surface in the Existing Phase.
Grade the topo surface using "Copy Internal Points."
Note Cut and Fill Volume is reported in the properties of the graded surface. Note this volume.
Split the surface ( as Case A 2. )
Note the Cut Fill Volumes of each of the newly created topo surfaces. Compare the total of these 2 volumes with the total volume at item B3 . Note that there is a significant variance.
In case B, splitting the surface will obviously create new boundary points. Using Copy Internal Points should force these boundary points to remain constant. While realizing that Revit is not intended to emulate the performance of a Civil package, the difference in volume reported in Case B is disturbing and the problem noted in Case A appears to be a bug.

[Alex Page]

Arent you meant to create a copy of your site in a previous phase?

[beegee]

You need to have the topo in an existing phase before grading as the grading tool demolishes and creates a new surface in the current phase.

If you're happy to lose the original surface, you can continue with the grading tool and the surface in the current phase.

[Mr Spot]

Hmm that's a bit worrying... Not that i've ever had the need to use this information, it would be nice to know its correct.

[lev.lipkin]

Confirming current limitation that each graded Toposurface should have same extent or be contained in the extent of existing Toposurface for cut and fill values to work.
Sorry for trouble, and nice catch!