Wednesday, February 18, 2009

Site Toposurface - Graded Region - Net Cut Fill

While attending a Revit Structure user group in San Diego (last week), my first chance to visit finally, Behzad was demonstrating some of the new extensions, the Bridge Extensions content available via your Subscription account at Autodesk.

He showed something that, on the surface (pun intended), doesn't dawn on most users. The graded region tool isn't the only way to get your Net Cut/Fill results. This is true because Revit really only cares that one surface is existing and another is in a future phase. In other words you can model one surface in an earlier phase and model another one in a later phase and the properties of the newer surface will show the net/cut/fill values compared with the earlier surface.

One condition: New surface must not be created outside the boundary of the earlier surface. If it is...it won't compare them, no cut/fill result.

3 comments:

troels said...

Funny, I read that just yesterday - in Help no less. Just seached for "site" :)

Nicholas said...

I have found that the two sites cannot share the same boundaries either. When I tried to do a cut fill on an entire site the new and previous versions did not relate (similar to the new boundary being outside the old)

Steve said...

They share the same boundary when the Graded Region tool is used so I suspect that it isn't that specifically. More likely is that it is can be difficult to faithfully match the existing boundary by picking points.

If you really need them to match then the graded region tool makes the most sense. Not using is useful when you need to create and merge a few surfaces to arrive at a "complete" surface.