1. Apparatus for shape measurement, comprising: (a) a laser projecting device, said device comprising at least one line laser light source, (b) a single image capturing device and (c) a computer, said computer including: means for detecting at least one intersection from an image sequence captured by said image capturing device fixed stationarily while moving said laser projecting device, said intersection being lit by the at least one line laser light source on at least one image; means for providing a plurality of equations, said equations being derived from the fact that a line of sight and a laser plane meet at the intersection by using unknown parameters of 3D position of the intersection and the laser plane, said laser plane being a plane representing said at least one line laser light source; and means for calculating the 3D position of the intersection and 3D position of the laser plane by solving simultaneous equations made of said plurality of equations by a nonlinear optimization method.