Abstract: According to the present invention, even if an analysis target has a complicated shape, for example, two or more cutting surfaces, elements can be automatically extracted therefrom without reducing any analysis accuracy. For each voxel interfering with shape data, an interference polygon is created inside the shape data using interference surfaces between the shape data and the interior of the voxel. After the interference polygon is created, a divided polygon is created by moving one of the vertexes of the interference polygon, which has a predetermined property, to another vertex. The divided polygon includes the vertex that has not been moved and vertexes of the voxel inside the shape data. An element of a predetermined shape is extracted on the basis of the relationship between a plurality of vertexes of the divided polygon.

Abstract: According to the present invention, even if an analysis target has a complicated shape, for example, has two or more cutting surfaces, elements can be automatically extracted therefrom without reducing any analysis accuracy. There is included an interference polygon creating step S3 of creating, for each voxel interfering with shape data, an interference polygon inside the shape data using interference surfaces between the shape data and the interior of the voxel.