Most handheld 3D scanners either use structured light or laser triangulation technologies. Often, these technologies are paired with photogrammetry. Let’s take a quick look at how these 3D scanning technologies work.

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Structured light 3D scanning

In this case, the handheld 3D scanner projects a pattern of light onto the object. Its camera then takes a picture of the object. That way, the 3D scanning software is able to compare the original pattern to the projected one, as it deforms when it hits the object’s surfaces.

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Laser 3D scanning

Similarly to the structured light method, the 3D handheld scanner projects laser lines onto the object. The software then calculates how much time it takes for the laser to bounce back to the 3D scanner, and from what angle.

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Photogrammetry

Photogrammetry involves taking several overlapping pictures of an object from different angles. The software then compares each photo and is able to determine the object’s geometry. In handheld 3D scanning, photogrammetry can be used for two reasons:

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• To increase accuracy: When used with markers, the photogrammetry module identifies the location of each marker to provide a sort of “skeleton” to then fill in with laser or structured light scanning.

• To capture colors: Photogrammetry cameras on handheld 3D scanners are often used to capture colors, also referred to as “textures”. The software creates a texture map, which it wraps around the 3D model.