Understanding the science behind the magic of 3D scanners
There are a few different methods to scan objects for the purpose of creating a 3D model, or to record 3D information of a landscape. There is no ‘best’ 3D scanning technology, each method solves unique problems to provide the best solution within different contexts.
The 3D Laser Scanner - 3D digitizing with the power of lasers
The most popular kind of scanner for consumer use is the 3D laser scanner. Laser scanning combines two sets of information to create a point cloud of an object’s surface: data from a laser being shone on the object, and data from another sensor (typically a moving camera, or two stationary ones). 3D scanning software stitches these data sets together using the known distance between the camera’s position and the laser’s source to generate a model’s points. Building 3D geometry from a laser scan requires detecting where the laser line falls in the images captured by the camera during scanning. The laser line is usually the brightest pixel of an image, but sometimes there can be other light sources captured. A stationary scanner can tell the laser line from everything else by cycling the laser on/off, creating a trackable difference between it and other lights captured during scanning.
Thousands of individual points are captured during a 3D scan. Like a regular camera, a laser scanner can only capture what is in its field of view. The captured points record everything from surface detail and texture to color, creating a direct representation of the scanned object. A captured point cloud is not a watertight digital object until its points are meshed into surfaces. The meshing process calculates how the points relate to each other in order to join them together into surfaces. An example of this is the prosumer Matter and Form 3D desktop scanner.
Benefits of 3D scan
- Fast, ultra-accurate results, reducing your time to market and cutting labour and material needs—saving you both time and money! When compared to traditional hand measuring methods, 3D scanning services are exponentially more efficient, quick, accurate, and detailed.
- Complete measurement data of the entire surface of object, verifying that the as-built part matches CAD model. Discovering any defects or deviations from the design-intent model will allow to readjust sooner and keep project or production on track.
- True CAD models for FEA testing of actual geometry to correct problems before parts go into production. This application can allow to conserve valuable resources and manpower.
- CAD models to validate tooling, even when no current models exist. Because 3D scanning is non-contact and non-destructive, it can safely and effectively capture data for unique, delicate, complex, or tiny parts and prototypes.
- Profile data of the whole part so assemblies can be digitally put together, revealing inaccuracies and interferences.
- Customized digital models of parts in whatever format required, with whatever level of detail, colour, and texture. We can convert raw 3D scan data into a SOLIDWORKS CAD model, for example.
We can deliver in many native formats
Structured Light Scanning -
Projecting patterns of light for a 3D model scan
Structured light scanning is not as dependent on texture variation to get a good 3D scan. In this method, one of the camera positions used in stereo vision and laser scanning is replaced by a projector that projects different light patterns (providing its own texture) onto an object’s surface and recording how the object distorts those patterns. Model points are created using the known camera position and information from the light pattern hitting the object. To be effective there needs to be an exact one-to-one relationship between the projector and the camera’s pixels. Structured light scanning is used in facial recognition technology, reverse engineering, design, manufacturing, and remote environment recognition.