Apparatus for processing concave shape of three-dimensional shape using polygon mesh and program for processing concave shape

摘要

PROBLEM TO BE SOLVED: To eliminate the need for a user to view a three-dimensional shape on a screen to search for a recessed shape, thereby allowing easy detection of a recessed shape present in the three-dimensional shape.SOLUTION: Provided is a three-dimensional recessed shape processing apparatus, comprising: an expansion processing unit 11 for expanding each of polygon meshes making up a three-dimensional shape by a specified distance in a direction of its front-oriented normal line; an intersecting portion detection unit 12 for detecting an intersecting portion in the expanded three-dimensional shape; and a recessed shape detection unit 13 for detecting a polygon mesh before the expansion in the intersecting portion as a component of a recessed shape. Using the property that if a polygon mesh making up one plane of the recessed shape is expanded in the direction of the front-oriented normal line, it intersects, on the same one plane of the recessed shape, a polygon mesh expanded from another plane present at a distance twice or less the specified distance from the one plane, the detection of the recessed shape can be automatically performed through the detection of the intersecting portion.SELECTED DRAWING: Figure 1