Lately a lot of Civil 3D and Revit users have been inquiring about how to make the two softwares work together on the same projects without going through painstaking measures. With the 2011 versions of the two products, interoperability is not just possible, but it is easy to make happen as well. Civil people will actually like what can be accomplished inside of Revit to ensure that the files interact nicely. Bottom line is that if Revit users take the time to do the initial setup that is available to them, the lives of Civil and Architectural people working together on projects can be so much nicer than in the past. The phrase from an old television commercial comes to mind; “Calgon, take me away!” Ok, maybe it’s not as drastic as that, but it used to be such a pain to coordinate the two disciplines! Civil people! Gather ’round as we discuss issues we can all relate to with past projects. I remember things like, “We have to scale the Architectural stuff up to get it to come in correctly.” “Zero,zero brings the Architectural drawings in way off in East Osh Gosh somewhere!” “The building footprint from the Architectural drawing is rotated to something they call Plan North. It is not rotated for the real world.” Guess what Civil people?! It does not have to be this way if the Architectural people you are working with are using Revit! In this blog, I will point out capabilities that Revit has just for your knowledge, rather than going into technical details since most Civil people don’t use Revit anyways.
First of all, as Civil people are well aware of, Civil base drawings are usually tied to coordinates based on a survey. We tend to go nuts when these drawings are moved, rotated, etc. Guess what!? This does not have to occur when Revit users bring the Civil dwg files into Revit. They have commands not only to import the dwg file but they can also “acquire coordinates” from a dwg file as well. What does this mean? Whatever coordinate system the dwg file is set up in can be the controlling coordinates for the Revit project! No more move this, rotate this, etc. Also, Civil people can call out a known survey point or monument in their drawing with a coordinate on it. Once it is imported into Revit and coordinates are acquired, the Revit user can inquiry the coordinates of the known point and they will match!
In Revit, there are two points that the users have control over; 1. survey point 2. project point. Here are the differences; 1. the survey point is the control point from the Civil drawing file. This is something that the Architectural people have to allow Civil to maintain the control over for this to work seamlessly. That “relinquishing of power” can be the most difficult part. 2. the project point is a point that is somewhere on the building for the Revit user to use for building coordination with the other disciplines such as MEP and Structural. This could be a specific corner that is used to line up drawings on. Once all of the drawing coordination has been set up, the Revit user can export out to a file format known as an adsk file. This file can be imported directly into Civil 3D to show the building footprint in plan view, and the 3D building in a 3D view. Here’s the good stuff for Civil people regarding this adsk file; if the Revit user exports AFTER coordinates are acquired, then you will be able to import into Civil 3D using zero,zero and it will pop in where it is supposed to! Also, if they already have a known “Z” for the site, they can plug that into the export as well. And finally, if utility connections have been established (usually just a bit later in the project) that info can be exported as well.
Another thing worth mentioning is that Civil 3D surfaces come into Revit just fine. In the figure below, I imported a dwg file into Revit and merely turned off some layers to view the contours that are seen. I did not have to explode anything, or extract polylines as many people have thought are the only possible ways to bring contours into Revit. Those contours are still part of an intact Civil 3D surface.
The features discussed in this blog should make the coordination of projects between the Architectural and Civil disciplines much easier than it has been in the past.