Scan Your Horizons

By Will Rourk

Imagine obtaining a 3D model of a building without modeling it …

Well, we’re not quite all the way there yet, but laser scanning will get you closer to that reality than you think. Especially now that this technology is much more approachable than it has been in the past. Laser scanning is a method of obtaining digital data from the real world by scanning the surface of physical objects. Those objects can be as small as museum artifacts, as big as a building or as vast as a mountain landscape. A laser flashed onto the surface of an object creates a mass of points in space called a point cloud that can be easily converted into an object model for your 3D CAD program. In the not so distant past, the equipment and resources to do this kind of survey work was quite expensive and technologically challenging. But now the technology has matured to a more consumer level, making it a viable option for most design offices. In this article we’ll find out who the laser scanning service providers are in your area and how they might help your office streamline your modeling workflow.

This point cloud scan is of excavated ruins of a tavern in Williamsburg, Va. Image courtesy of Direct Dimensions.

In Baltimore, Direct Dimensions Inc. is widely known for having scanned the Liberty Bell and the Tomb of the Unknown Soldier, but they have also engaged in scanning projects that range from many different scales. At any level of detail, the scanner is able to provide 3D data that can be used for any standard CAD model down to sub-millimeter accuracy. Charlie Matlin of Direct Dimensions defines model end product delivery upon two conditions: “You can capture a site ‘as-is’ or you can provide a design intent, perfected model for use to get funding or for a special presentation. The results are compatible with most software like for example Revit for architecture and Solidworks for engineering.”

Speed and accuracy are two major factors when considering laser scanning of existing site conditions. Andersen and Associates, out of Blacksburg, Va, are recognized for their large-scale scanning projects like the Norfolk Southern Heartland Corridor, which involved scanning numerous railroad tunnels. But their services have applied to varying scales of spatial input from theater interiors to the utilities infrastructure of MCV Hospital in Richmond. As Joe Conrad, scanning tech specialist for Andersen explains: “When the client doesn’t have maps and need plans, a quick scan in 5 minutes can get the job done fast without interruption. Time consideration is an important factor in project set up.” Laser scanning is a convenient option when a survey needs to be done of existing conditions during normal operations time at a working project site. As Conrad relates: “You can just set the scanner up and it scans away, but you’ll want to set it up so it doesn’t interfere with the workflow that continues to go around the scanner.”

The rendering derived from the point cloud will assist designers in replicating a Williamsburg tavern that once hosted debates among the founding fathers, including George Washington. Image courtesy of Direct Dimensions.

Laser scanning technologies have also proven to be a fast and convenient way of providing 3D data for presentation models that can be used to obtain funding. Precision Measurements, Inc. out of Virginia Beach, scanned the train depot at Norge, Va., to provide a fast model for VDOT to provide a simulation for the James City County local government that the structure could be moved and then placed exactly back in its original location. In another case, PMI worked with York County government officials to scan beaches for sand erosion loss to obtain funding from FEMA after hurricanes have struck. As Kelli Stamm of PMI explains: “When hurricanes strip out the sand, York has to send requests to FEMA for funding, and scanning can help prove the volume of sand needed to replace if the beach is scanned before and after a hurricane.” York is also provided with archival data of existing site conditions that they can keep on hand for the future.

Although, laser scanning has become a much more approachable technology than in the past, it is still not a simple one-step process. The laser scanner can provide raw 3D data as a point cloud, but then it needs to be converted into a usable, CAD-ready object model. There are services available for that as well. Laser scanning service providers offer data manipulation of scanning results, but there are 3rd party solutions that deal with handling the data in a way that is optimal for a design office. Michael Tardif, director of IPD systems for Grunley Construction Company in Rockville, Md., relies on Intelisum data management services. According to Tardif, “There is a tendency to assume that you can just scan and import a model into Revit, and Boom! you have your BIM. Intelisum has the best algorithm to convert point cloud data to a BIM model that is very faithful to existing conditions.”

For the more adventurous there is the option to buy scanning equipment directly and develop these services in-house. One of the more popular scanners out there today is the FARO Focus 3D. It is a highly portable, relatively affordable device that can scan from a distance of 120 meters to a level of accuracy of 2mm all for a price around $40K. Greg Richards of FARO Techologies Inc. describes the newer scanners as “designed for extreme accessibility and ease of use. The Focus 3D has a touch screen interface that’s easy to use like a smart phone. Just stick it onto a standard photography tripod and scan. There’s even a big green button to push so you can just start scanning.”

So how do you get started with laser scanning? Most services providers offer an online Web form to describe what you need scanned and the context of your project. Pictures of the site in question are very helpful as well. Or, of course, you can call directly to any of these offices and the process for obtaining fast, accurate, and affordable 3D data can commence.

For more information on how to contact the professional service providers mentioned in this article visit Will Rourk’s blog.

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