Projector-type 3D scanning seems very functional, but I would expect it to lose accuracy as the object size decreases. So for scanning small objects (such as Lego), Lego genius Philippe Hurbain has come up with a scanner made of lego.
Philippe’s instructions also includes (under “3D reconstruction”) a technique for creating a “complete” 3D model out of several combined scans, using open source 3D software MeshLab.
More information (and via) Dansdata