From reflected light to coordinates
An optical 3D scanner projects or observes a pattern on an object and uses calibrated cameras to calculate surface positions. Each valid measurement becomes a point in three-dimensional space.
The scanner does not capture the entire object at once. Software aligns overlapping frames while the scanner or object moves, creating a larger point cloud.
Structured light and laser lines
Structured-light scanners project a wider pattern and can capture a large area quickly. Laser-line scanners concentrate energy into narrow lines, which can improve edge and difficult-surface capture.
- Infrared structured light: comfortable for people and large feature-rich objects
- Blue structured light: short wavelength and controlled full-field detail
- Blue laser lines: mechanical detail, edges and darker surfaces
Tracking is as important as resolution
Feature tracking uses visible geometry, texture tracking uses color variation, and marker tracking uses known reflective targets. When the object provides too little information, the software can lose its position even if the cameras are capable of fine detail.
Point cloud, mesh and CAD
A point cloud is a set of measured coordinates. Meshing connects those points into triangles. Neither automatically becomes editable parametric CAD. Reverse engineering adds surfaces, sketches, dimensions and design intent after capture.
Sources and further reading
Where this guide starts
This article is an original Best3DScanner synthesis. The references below support the technical background; manufacturers do not control our conclusions.