Special Application and Prospect of 3D Scanning

      Around 2016, I was first exposed to 3D scanning technology; before that, in my cognition 3D scanning was mostly used for industrial design, landscape exploration and historical building protection.

3D scans in reconstruction project 

      3D scanner can create point clouds on the geometric surface of the object. These points can be used to interpolate into the surface shape of the object. The denser the point clouds are, more accurate models can create. This process is called 3D reconstruction. If the scanner can obtain the surface color, it can further paste a texture map on the reconstructed surface, which is also called texture mapping.

      At that time, my classmate was doing a research about facial recognition. He bought a handheld 3d scanner, which was a cheap portable device. It cost less than one tenths of a professional device that may cost several thousands. At the time, his use Delaunay mesh in grasshopper to easily directly convert the scanned point cloud into a curved surface. But with limited accuracy and too many edges and corners, it could not effectively smooth out a model that fits the face. Later he changed to use face feature comparison, which was much faster and more effective than comparing the entire faces with point clouds.

       Chirag Jindal from ARCLAB gave us a lecture about their projects with 3D scans and point clouds. Their practice is specializing in precise, digital replicas of buildings, landscapes, objects & events.

Into the Underworld: The Architecture of Katabasis

       In lecture, the underground cave exploration part was really impressive. In the past, digital exploration which used sound waves, magnetism, etc. to locate and describe the shape of caves below grounds. It was often disturbed by various natural factors. This was the first time I had a clear understanding of the digital 3D model of caves in real colors, which could help the use of the underground space a lot.

Cross section of intervention by Chirag Jindal

       In Chinese construction market, the future of 3D scanning technology is unclear for two reasons: one is the lack of popularity of BIM technology. Most architects and designers are still using CAD for 2D drawing. Only large design institutes have few professional BIM teams at the stage of construction drawings. And the construction teams rarely have the qualification to connect with the BIM system.

       The second is the lack of consciousness of historical building protection, which is gradually improving these years. As the cost of retaining and repairing is often much more than reconstruction. Besides some structures in the renovation of industrial plants, most historical buildings of general importance do not have the requirement of "repairing the old ones." So there is no need to use 3d scanning for recording.