PRODUCTIVITY CORNER: MicroStation and Google Earth10 Mar, 2006 By: Joe Croser Cadalyst
Google Earth gives AEC firms a new perspective on their MicroStation projects.
What is it about the number seven? It crops up in all walks of life. According to the Bible, the world was created in seven days. Many consider the number seven lucky, and in ancient times, the Earth sported its Seven Wonders of the World. We have the seven seas, the seven deadly sins, the seven ages of man and the seven notes of the musical scale. I could go on and on, but I think seven examples get the point across.
Sadly, only one of the original Seven Wonders of the World remains, the Pyramids of Giza; the others are long gone. Visiting the Pyramids always has involved quite a journey, depending upon one's starting point. But thanks to a technology from Google -- the Google Earth mapping service -- visiting the Pyramids now is a simple task achievable from the comfort of your own office chair. Open the Google Earth application and type in the word Pyramids, hit the enter key and watch as the world whizzes by beneath you as you are transported to the outskirts of Cairo and given a bird's eye view of the Pyramids.
Google Earth is a virtual globe that sits inside your PC enabling you to point at and zoom to any place on the planet that you want to explore. One can also access the Google search engine to show local points of interest and facts. It is very cool! So I embarked on a global Google Earth tour. I started from the Pyramids by entering my office address in Exton, Pennsylvania. I flew high above the African continent and then crossed the Atlantic to zoom in on the front of my office. Next on my grand tour was our Asian office in Beijing, China, and I concluded my round-the-world trip by stopping in at our international operations headquarters in the Netherlands.
I headed for home via the Big Apple, planning a quick circle around the Statue of Liberty. As I closed in on Manhattan Island, buildings started to sprout skywards as the 3D city model reached for the sky. And it struck me that this kind of integration of CAD models and aerial mapping photography would have real benefits to users of CAD modeling tools such as MicroStation. As luck would have it, I was not alone in my appreciation.
Ray Bentley is a strong advocate: "The Google Earth mapping service is an extraordinary tool that provides the user with a 3D interface to planet Earth that is complemented by a large range of geographical data." Ray liked it so much, he wrote an interface from MicroStation to the Google Earth tool to enable users to take MicroStation DGN models from the native CAD environment into the Google Earth tool's game-like interface using the KML file format.
"We find ourselves in a unique position, thanks to our extensive GIS products and the popularity of MicroStation for 3D modeling," Bentley says. "As a result any MicroStation user can export complete 3D models with geospatially located 2D data directly to the Google Earth tool. This makes our integration entirely different from any other single point solution."
KML is a dialect of XML that is designed specifically as a conduit for providing information to the Google Earth mapping service. It is a 3D file geometry format that is somewhat similar to the U3D (universal 3D) format used to represent 3D MicroStation geometry in PDF files. However, KML differs from U3D in that it is primarily intended to represent geometry on a macro scale, whereas U3D is focused on accurate micro-level visualization of 3D CAD geometry.
So why might you use a Google Earth tool to visualize MicroStation models? Why not just view the models in the MicroStation CAD environment? The Google Earth mapping service allows AEC firms to gain a new perspective on their MicroStation projects and to leverage their DGN data in an entirely different environment. From site-location feasibility studies to land use impact analysis, MicroStation users rely on a plethora of geospatial data in planning and marketing projects. Now with the Google Earth integration, MicroStation users have an efficient and compelling way to distribute and communicate that data to project decision makers.
Some other features available to MicroStation users when exporting to the Google Earth tool include carrying transparencies, saved views and GIS mapping data and utilities information from the DGN model into the KML file. tool in MicroStation will automatically follow your movements in the MicroStation DGN file and take you to the same geographic location within the Google Earth tool. These functionality additions mean that MicroStation users can share their models on the global stage with anyone, anywhere at anytime. Standard features also include the persistence of switchable level structures and DTM (digital terrain modeling) information.
Google Earth Pro can already import DGN data but only for 2D information and only for users with the Data Import module. Google Earth Pro was quick to include support for MicroStation's 2D CAD data due to the ubiquity of the DGN file format among mapping and GIS professionals. "Taking 3D DGN data from MicroStation and converting it to the versatile KML format will be a huge benefit for both MicroStation and Google Earth professionals in the AEC industry, extending the reach and benefit of users' data with detailed models and sophisticated GIS information," Bentley says.
Finishing my virtual tour of Manhattan, I headed for home realizing that I had flown right around the world. I passed over all seven continents using the Google Earth tool, and I mused further over the concept of seven. We are told that there are only seven degrees of separation between us and anyone else on Earth, so now I wonder how technology will help to reduce this distance between people and continents.
As I mused, my mind and eyes wandered. I glanced out of the window and saw the flagpole in the parking lot with the Bentley flag flying in the breeze. I started to count the number of letters on the flag, and I was not at all surprised when I reached the letter Y and the number seven.
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