A modeling device obtains three-dimensional coordinates from a measurement device for taking three-dimensional measurements of the three-dimensional structure having faces to produce model information of the three-dimensional structure, and includes a face extractor, a vertex extractor and a model producer. The face extractor produces a plane equation describing a face based on coordinates of each measurement point of the face. The vertex extractor extracts a point simultaneously satisfying plane equations describing adjoining faces as a vertex shared among the faces. The model producer produces model information representing the three-dimensional structure based on plane equations and vertexes. The face extractor determines a plane equation by recalculation based on measurement points existing in a range of a prescribed distance from a plane candidate.
展开▼