We often get questions about transferring data from Revit to other Autodesk applications. There are many workflows out there that you can go through. One that is very interesting to me is taking a Civil 3D site model and using it in Revit for your topographic surface. It’s also a challenge that seems to be coming more and more prevalent and one that many Architects face while working in Revit. So how do you take a Civil Engineers Site design and bring it into Revit?
The answer is importing a Civil 3D DWG file into Revit Architecture and using Site tools to create a surface from that file.
Things get a little bit more complex if you actually try to do it and get even more complex as you attempt to go into other details like shared coordinates. I’m not going to cover shared coordinates here (that’s a whole other topic), but importing a just a simple site from Civil 3D into Revit has its challenges.
All a Civil 3D users really needs to do is save the Civil file and send it off to the Architect. The Architect can then link that file into Revit and create a site using the site tools in Revit Architecture (more on site tools later). The one limitation with this process is that the civil Engineer needs to set a system variable in Civil 3D so that Revit Architecture can read all the Civil Data. Setting proxygraphics equal to 1 in Civil 3D and then saving the drawing will let the Architect see all the Civil stuff in Revit Architecture.
This method works very well and everyone can be happy most of the time, but if everything was great all the time, I wouldn’t have a job (believe me, sometimes I wish that was the case).
Civil 3D files can contain a lot of data and a lot of this data is not needed by Revit Architecture users to create a site. All that they really need are contours, or a TIN surface. Revit can use either to create a topographic surface. So an engineer can just give the architecture the TIN surface or the 3D contours and the Architect is set to create their site. By limiting the data that is used, your Revit projects will be smaller and there is less chance of a problem. So if you can clean up that DWG file before importing it into Revit Architecture you will save some headaches.
A great tool within Civil 3D for cleaning up the drawings for others not using Civil 3D, is the Export to AutoCAD command. This command strips out all the extra data that other applications can’t use and only leaves behind the AutoCAD data that Revit can read. Performing Export to AutoCAD creates a separate DWG file that can be sent to the Architect and they will not know the difference.
Also, it’s nice to clean up the DWG file a little bit before inserting it into Revit. It’s like organizing your desk before leaving for vacation, when you come back everything is in the right place. Run an Audit, and Purge on the file in AutoCAD to remove any errors and get rid of anything that was deleted that is no longer in the file. Also, if you can delete any of that extra data that isn’t needed it’s a big help. Be careful of things floating out in space away from the site, these things are read by Revit and can cause the DWG file to look bigger than it is.
The next step is importing this surface into Revit Architecture and using it to create a Topographic surface. For this a video works pretty well so watch it by clicking here.
Some Importing rules to remember…
- Do not use “Current View Only” when importing. This will prevent you from using the DWG file to create a Toposurface
- Use “Center to Center” for the placement method. You don’t need to insert the DWG at the actual coordinates because you can used Shared Coordinates to get this information into Revit. If the coordinates of the DWG are too large, Revit will automatically place the DWG file Center to Center anways.