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).
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.
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.
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': [1]
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.
- "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.