By now most people have heard of 3D printing. From spare parts to comic book heroes to entire working vehicles, the stories of how micro-manufacturing has burst into industry and changed forever the way we design and manufacture machinery, furniture and even medical devices are everywhere.
What is somewhat less famous but no less dramatic or useful is a process called “3D scanning.” If 3D printers are the factories, 3D scanners are the mold makers and machine shops. Using technology first employed in the industrial LASER, a 3D scanner can take a three dimensional photograph of an object and convert it to the spatial information necessary so a 3D printer can reproduce it with exact precision.
Essentially, it is one-half of a copy machine for physical objects. Here are some interesting facts about how it works.
Scanners Use LASER Light
One of the reasons a 3D printer is able to utilize such precision is because devices like 3D scanners can measure every surface of an object in exact detail. The process works through producing something called a mesh. The mathematical data specifying where each point on the surface of the object exists in arbitrary three-dimensional space is recorded and then used to reconstruct the object.
The LASER is there to “touch” each point on the object so it can be added to the mesh.
Scanners Measure Angles
One of the chief means of interpreting the light reflected from a physical object is to measure the angle of its reflection. The software that operates a 3D scanner can measure these angles to determine the physical shape of the object being scanned. Think of it as a sophisticated way to know what direction an object is facing. The human brain will use depth perception and shadows to analyze an object. The scanner uses a reflected LASER beam.
Scanners Use Sensors
One of the most powerful methods 3D scanners can use to generate the physical data necessary to recreate an object is to employ a set of sensors. In most cases, these are specialized cameras placed at a fixed point relative to the LASER itself. When the beam is fired, the software can use mathematical principles to determine the distance and angle of each point where the LASER is reflected. Once all of these points are gathered, they produced a highly detailed virtual representation of the object being scanned.
The most fascinating thing about 3D scanning is the fact all the technology used to engineer it was invented many years ago. The concept of using electromagnetic reflection to detect and track an object at distance was invented more than 80 years ago. It’s called RADAR. The principles of the 3D scanner are built on similar technology with more precision and an entire world of new uses.