Patent ID: 7098909

Claim:
An apparatus for automatically generating an outer or rooftop shape of a three-dimensional structure from a plurality of points having three-dimensional coordinates containing height information, comprising: means for constituting a point group by collecting such points that three-dimensional distances between said points are within a predetermined threshold or two-dimensional distances and height differences between said points are within predetermined thresholds; means for detecting a polygon that includes the points of the point group at a minimum area from at least one of a plurality of predetermined polygons; and means for generating one of an outer shape end a rooftop shape of the three-dimensional structure based on said detected polygon having the minimum area, wherein said means for detecting the polygon having the minimum area gradually rotates one of all points of said point group and at least one of the predetermined polygons by a unit of a predetermined angle so as to find an angle at which said polygon has a minimum area.