Infrared 3D scanning
Depth capture using invisible infrared light — fast indoors, difficult in sunshine.
Infrared scanners project a pattern of invisible light into a space and measure how it deforms across surfaces. From that deformation the device computes distances and therefore the geometry of the room.
The method is fast and highly reliable indoors — many 3D cameras for building capture rely on it. The weakness shows outdoors: sunlight itself contains a great deal of infrared and drowns out the projected pattern, making measurement imprecise or impossible.
For outdoor capture and long distances, LiDAR or photogrammetry are the better choice. Glass and mirrored surfaces remain difficult for both methods.