TECHNOLOGY
BY MAUREEN FLYNN, JD
3D Documentation Technology in the Construction Industry
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D documentation has become a standard in the construction industry. The technology allows for the easy use and incorporation of 3D documentation into all stages of a project, from concept and design to construction and project delivery. 3D laser scanning (3DLS) is a non-contact, non-destructive technology that digitally captures measurable documentation of as-built structures and surfaces and brings them into the computer world as a three dimensional representation. The laser scanner captures an object’s exact size and shape using a line of laser light (people and eye safe). The point cloud data produced through the use of this technology creates an image similar to a pixelated black and white photo. Those “pixels” are actually points, each with an x, y, z coordinate value. Point cloud data can be used to create: 3D models, 2D plans, topography and more. Created in the 1960s, the equipment for the original 3DLS technology was large, heavy, cumbersome to transport and challenging for the user to maneuver. Improvements in technology have Maureen Flynn, JD, is the business development manager for Haag 3D Solutions, a full-service 3D documentation firm providing a multitude of services to professionals in the AEC industry. To set up an AIA accredited lunch and learn, or to schedule a conversation, she can be reached at 856-206-7756 or at mflynn@haagglobal.com.
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Spring 2017
reduced the weight, size and complexity of the equipment; modern versions no longer require light, weigh only two pounds, often need just one field technician to operate, and offer full color panoramic images overlaid on highly accurate point cloud. As with any technology, there are limitations with laser scanners. Advancements over the last 50 years have made significant improvements, reducing or eliminating many limitations. Since laser scanners work on line of sight, they cannot see through objects or surfaces, but properly trained field crews will remove or work around those obstacles by performing additional scans. Reflective or shiny surfaces are an issue for laser scanners. Rather than capture the surface, the laser reflects off it and can bounce in another direction. Baby powder and certain aerosol sprays can be used to reduce the reflectivity and allow the scanner to capture the object’s surface, as will any dust or dirt that has settled on the object. Water is a unique challenge for laser scanners. Most often, the water absorbs the energy of the laser leaving what looks like a black void in the point cloud. Surfaces with pools of water (low spots on concrete, puddles on pavement) are areas that will not have accurate point cloud data. The 3D equipment providers can help determine whether the water will interfere with the scanner’s goal, and the best ways to work around the water feature. Whereas extreme temperatures historically were an issue for laser scanners, modern laser scanners can function properly with ranges in temperature from -20°F to over 100°F. Steam, rain, fog and dust continue to be factors of consideration when performing a scan. The result is referred to as “noise.” Noise is essentially a data capture of the moisture or dust that is in the air rather than the surface being captured. Advancements in some scanners allow for the “noise” to be cleaned out of the point cloud imagery. Today, scanner set-ups can be completed in three minutes, capturing one million points per second – a major improvement over the hours or days it used to take to capture a surface. Advancements in software technology allow for data