Dear Vector2
What our friend is saying about a Lisp routine that does the job of creating the topography is true. I wrote one for me, too, and I explain its use to my students in my courses. Revit provides 3 ways of making a site: 1) By manually adding points with elevations , 2) By importing a drawing, and 3) By reading a list of points.
The method that you are proposing (tracing over) has to do with option # 1, but it will be extremely awkward to trace over an image of a site plan, not only painfully slow and inaccurate, but also risky and unprofessional. Have you really tried? Those plans have some difficult curves, it will be a nightmare to trace it over, don't even suggest that.
Option # 2, importing a drawing; you bring a 3D wireframe of a site plan, and then tell Revit to use that import to create the topography. Once created, you may erase the imported drawing. Nothing wrong with that, if it works.
The other option, # 3, is the one that works with the Lisp routine. This option has the advantage that you don't need to import any CAD drawing, which is what you and others are against to. All you need is some previous work in AutoCAD before going into Revit. In AutoCAD, you need a 3D wireframe of your site plan; have all the contours elevated as per the actual elevations. Then, in AutoCAD, you run the Lisp routine. It only takes seconds to generate a list of all the x,y,z coordinates of the first and endpoint of every line or polyline segment. The routine saves the list in a .txt file. Then close AutoCAD, go to Revit > Site view > Massing and Site tab > Toposurface > Create from import > Specify points file > select the .txt file created by the Lisp routine > and Voilá! ...your topography is created in an instant. The result is accurate, since it is created with actual coordinates. Now compare this with tracing over an image!
Alfredo Medina
Online training of
AutoCAD & Revit Architecture
www.planta1.com
