1. A discrete linear space sampling method for generating digital 3D models comprising: acquiring a plurality of digital images of a subject from a respective plurality of image sensor positions near to an image sensor location; identifying candidate 3d-spels, each 3d-spel being an image pixel corresponding to a common point on said subject; rejecting candidate 3d-spels based on a differential analysis of the candidate 3d-spels, the remaining 3d-spels forming a set of accepted 3d-spels; calculating 3D coordinates for each accepted 3d-spel, thereby forming a point-cloud of the subject.