Today Robert Lipman of the National Institute of Standards and Technology shared an example of a CIS/2 file (a structural steel product data model) displayed in Google Earth. It’s a good example of how to take advantage of Google Earth to display a design, but in practice it was an interoperability nightmare. The data was stored in six separate file formats from start to finish.
Lipman's structure is a partial model of the structural steel for the rebuilding of Soldier Field, a stadium in Chicago. You can download the file and view it in your own copy of Google Earth, if you like. To start, go to http://cic.nist.gov/vrml/cis2.html. On the page, at the right under What’s New, click on “CIS/2 model in Google Earth.” There is a brief explanation of how the CIS/2 model was converted to a Google Earth file. (More on that in a moment.) There are also some instructions about how to use the model in Google Earth and a screenshot of what it should look like.
So, how did this structural steel model come to be viewable in Google Earth? First, the data was part of a SAP2000 database. (One.) The information was extracted from SAP as a CIS/2 file. (Two.) The CIS/2 file was translated to an IFC file with the CIS/2 to VRML and IFC Translator. (Three.) Next, the resulting IFC file was imported into Autodesk Architectural Desktop. (Four.) Then Lipman used Avatech Earth Connector to generate a KML file (Google Earth model) from the data. (Five.) Lipman then added in a viewpoint and a placemark (to georeference the data), and saved the results as a KMZ (Google Earth data) file. (Six.)
Google Earth is hot right now, but not everybody has the time or temperament to pull model data in and out of six separate file formats. Avatech Solutions has done the AEC community a good deed by publishing their ADT-to-Google Earth converter and making it free. I hope Lipman’s exercise, and Avatech’s example, convinces others to contribute similar data converters. A direct CIS/2 to Google Earth file would be a good start, as would an IFC-to-Google Earth connection.
I already have Google Earth on my computer, so I downloaded the file to my desktop, and then double-clicked on the file. Google Earth started up and the globe spun around and zoomed in on the model. If you don’t have Google Earth (the basic version is free) you can get it at http://earth.google.com/.
“As an added bonus,” says Lipman, “there is also a model of the AISC connection sculpture hiding someplace in Chicago. Think about it and it should be easy to find.”
--RSN