Hybrid 3D scanning systems work by combining photogrammetry and structured light methods. This is the technology that Twindom uses on it's full body 3D scanners used to make 3D portraits.
A DSLR full body 3D scanner relies on photogrammetry to create a 3D scan. Photogrammetry works by finding shared features between multiple photographs to calculate depth. It is predominantly used in the visual effects industry.
Turntable-based 3D body scanners rely on the same technology as handheld 3D scanners (structured light), however they typically use less expensive hardware such as a Microsoft Kinect, Primesense, Asus Xtion, or Intel Realsense sensor to calculate depth.