3D scanning

3D scanning is the process of making a 3D file from a statue, model, or building.

Structured-light scanning

This is making a 3D file of an object just using a camera or a camcorder with either 1) a projected grid from a video projector or 2) a projected line(s) from low power laser light source (generally, a laser-pointer or similar).

DIY

Splinescan is free and open source software. It has reached a high level of polish and sophistication. The website and documentation does not yet reflect this. See also the RepRap local documentation stub Splinescan.

David Laserscanner is closed source, the kit requires €400 and a Windows computer. But you get a laser pointer and stepper-motor powered rotary table, and they've spent a lot of time on their website.

Commercial

There are probably a number of expensive solutions for doing this, based on good software, a camera, and a laser pointer. And good marketing.

Photogrammetry scanning

This is making a 3D file of an object just using a camera, or a camcorder, even without a laser-pointer-like light source.

Technically this is called 'photogrammetry' or more precisely 'object reconstruction': http://en.wikipedia.org/wiki/Photogrammetry

• http://grail.cs.washington.edu/rome/

• Bundler: Structure from Motion for Unordered Image Collections

• insight3d

• libmv - a structure from motion library

• http://en.wikipedia.org/wiki/Microsoft_Photosynth

Touch-probe scanning

• "Robot Arm Type": here a human guides a 'finger' of a device that looks like a robot arm over a model or sculpture. This deals well with overhangs and precise geometries like boreholes or outer diameters. Coordinate Measuring Machines, or CMMs are often built in this configuration.

| http://en.wikipedia.org/wiki/Coordinate-measuring_machine

• "Generic Touch Probe": we can mount a touch probe on a 2+1 axis machine like a CNC router, mill, or RepRap. This is convenient if we don't have a robot arm handy.

See also David_Project.