Laser Scanning Point Clouds with ARCHICAD 19

Recently Graphisoft hosted a webinar outlining an historical project where they used laser scanning point clouds and ARCHICAD 19 to produce as-built drawings of the Arizona State Fairgrounds Grandstand Building.

The 1938 WPA project built of concrete, steel, with some adobe, was missing original blueprints, so a set of high quality drawings were needed to support fund-raising and preservation efforts.

Philip Allsopp, chief design officer with Smart Pad Living, LLC (www.smartpadliving.com) and Senior Sustainability Scientist and Adjunct Professor at the Julie Ann Wrigley Global Institute of Sustainability at Arizona State University, presented a case study webinar about a groundbreaking use of drones, 3D laser survey and point clouds with ARCHICAD 19.

The resulting accurate as-built HABS (Historic American Building Survey) drawings of this important historic structure will also be lodged with the United States Library of Congress.

The manual measurements of such a project with traditional measuring methods would take 15-20 surveyors 3 months to complete—at an estimated cost of close to a quarter of a million US dollars, according to Allsopp. “Thanks to 3D scanners and drones, we can create point clouds and ARCHICAD 19 can align your project with 3D geometry information and eliminates problems that arise from manual input.”

The surveying project was completed in only four days, with post-processing taking only one more week.

Graphisoft’s vision is to provide tight integration between the three core components of its solution ecosystem: BIM Authoring, BIM Data Access, and BIM Data Management.

With ARCHICAD 19, users can save time with background processing that generates nearly instant model views, and save money by reducing field changes on renovation projects. ARCHICAD point cloud technology supports provides faster processing and error free building surveys using their scanning technology, individual feedback, better IFC based interoperability and collision detection.

Graphisoft Cloud offers true model based BIM collaboration environment for companies and projects of any size. BIMX Pro provides ultimate 2D and 3D integration.

“In the emerging field of HBIM – Historic Building Information Modeling, we and our partners are on the cutting edge of the use of this technology to document, simulate and improve performance of existing structures,” Allsopp noted. “In the AEC field we’re only fairly recently moving into large scale document and simulation of document performance. In electronic products they’ve been using simulation systems for years.  Our view and that of our partner companies is that this kind of simulation needs to take place in the construction industry.”

Since World War II, the land speculation and conversion of human habitats have been turned into real estate commodities and have all but eradicated social capital growth, that drives innovation, ideas and economic growth. The existence and maintenance of older neighborhoods, reusing those wonderful assets of community and enabling people to be human and interact with each other, is a critical factor in the efforts behind the HBIM factor and the historical preservation movement.

The Arizona State Fairgrounds in Phoenix have great meaning to thousands of people, especially those who live around them in historic neighborhoods. Built during the Great Depression (1930s with some buildings being added up to 2008), they are under constant threat of demolition and neglect, to make room for asphalt parking areas. Policies such as these are driven by public and elected officials who insist buildings pay their way rather than being the critical assets that support and often define vibrant and resilient communities.

One interesting factoid about the grandstand: the movie “Bus Stop” starring Marilyn Monroe was filmed in the grandstand.

The grandstand is a mix of reinforced concrete and adobe. The interior underneath the stands is a complicated structure to survey, according to Allsopp, quite demanding in terms of making sure survey levels are set correctly.

The main players involved in project are as follows: Arizona State Fairground Stakeholder Committee, consisting of the Arizona Preservation Foundation, Encanto Citizens Association, Encanto-Palmcroft Historical Preservation Association, TopPa3D (Paul Tice, CEO) Remote Sensing for the Future, Smart Pad Living and Arizona State University.

Arizona State professor Laura Allsopp of the Historic Preservation Committee has been working for years to prevent the wanton destruction of neighborhoods and buildings. “All these groups got together to discuss the necessary protection of the civic building,” said Phil Allsopp.

“In discussions with TopPa3D, the stakeholder committee launched a fundraising program to enable grandstands to be surveyed and documented using state of the art laser scanning drone-based 3D photogrammetry and ARCHICAD BIM that we use to create simulate models and new structures,” said Allsopp.

Workflow was a threefold process: ground-based scanning with the laser scanner, with the machine that produces laser beams at about billion per second in a large hemisphere to create the xyz points that are part of a point cloud. A single drone was used to fly a GPS pattern to do 3D photogrammetry for R&D purposes to make sure the photogrammetry could be integrated with point cloud data. Point cloud data from the scanner produces RGB data which means you get colored information in the point cloud.

“Interstellar discussion of time dilation is a neat piece of technology built into GPS units that deals with accounting for speed of light and how time slows down depending upon how close you are to the earth’s center,” Allsopp explained. “As you can see measuring two lines distance across the earth’s surface a to b, the closer you get to the earth’s surface, the more light gets bent by gravity. This light has a longer path to travel than if you were measuring the same distance several miles above the earth. To us, no matter whether high above earth or below it it seems the same to us, but it isn’t, unless GPS devices account for how gravity bends light the closer light is to the gravity field. Distance measures will be inaccurate because we’re measuring distance by the flight time of laser light coming back, so we need to make sure we’re accounting for time and distance correctly and it’s modified some by gravity. It’s how our cellphones and how our mapping systems satellite actually work.”

Next, point cloud scan data is imported into ARCHICAD and that enables you to use the well developed sections, plane and elevations capabilities as well as BIM modeling capabilities that reside in ARCHIDAD’s features.

“What we wanted from this particular process was to do the work rapidly, accurately and efficiently,” said Allsopp. “Images would be unobtainable from ground based surveys. They spray out essentially a hemisphere of 1 million laser beams per second, as the scanner traverses through its 360 degrees. Using ARCHICAD 19, the team imported 4 billion data points of the front and side scans of the building in less than a minute.

“Halfway through scanning the grandstand, we checked the point cloud files and saw that we had created well over a billion data points. ARCHICAD 19 read that data in about 30 seconds. Creating sections and elevations of the point clouds took no more time than any section or elevation takes in ARCHICAD – it’s a matter of seconds,” Allsopp said. “Having worked with some dedicated point cloud visualization tools, it is the only software I know that is able to handle, read and manipulate such a large data set so fast. Going forward, we will be using ARCHICAD extensively for creating orthographic images and drawings for the HABS parts of this important project,” he added.

Tags: 3D, AEC, Archicad, architects, architecture, BIM, building, building information modeling, CAD, Cloud, collaboration, construction, design, engineering, infrastructure, reality capture

Categories: 2D, 3D, 3D PDF, AEC, AECCafe, Archicad, architecture, BIM, building information modeling, Cloud, collaboration, construction, infrastructure, point clouds, project management, reality capture, site planning, sustainable design, virtual reality

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