Riken Corporation

Yoshinori Teshima

Kiwamu Kase

Shugo Usami

Akitake Makinouchi

Shuntaro Yamazaki

Masaya Kato

Yutaka Otake

A method includes: an input step of inputting boundary surface informationon an object to a computer using the computer; a grid sampling step of determining cutting pointswhere the boundary surface cuts across edges of a predetermined rectangular parallelepiped gridand normal vectorsof the boundary surface at the cutting points, and storing them in a storage unit as primary data; a D-polyhedron data generation step of connecting adjacent cutting points with a line segment to form a triangle one by one for generating D-polyhedron dataconstituted of triangles only; and a V-polyhedron data generation step of generating V-polyhedron dataconstituted of intersections of a plurality of infinite planes passing through the cutting points and whose normals coincide with the normal vectors. Any one of the D-polyhedron data and the V-polyhedron data is generated from the primary data, and the other is generated as a dual.

Method and program for generating boundary surface information

A cutting point calculation step defines the cell complex that contains the boundary data, and calculating a cutting point where the boundary data cuts an edge or vertex of the rectangular parallelepiped cell of the cell complex. A cycle formation step classifies the rectangular parallelepiped cells into a boundary cell having the cutting point and a nonboundary cell having no cutting point, acquiring a cutting segment between a cell surface and boundary data for each boundary cell, and forming a cutting segment cycle closed by connecting the cutting points and the cutting segments alternately in sequence. A cycle internal division step divides the inside of the cutting segment cycle into cycle inner triangles sharing an adjacent side, for each boundary cell. A simplification step of unifying a plurality of cutting points on each edge, and registering the cycle inner triangles in the cell, for each boundary cell.

Method and program for converting boundary data into cell inner shape data

By external data acquisition means using a computer, external data comprised of boundary data for an object is obtained; by external data input means, the external data are inputted into the computer; by cell dividing means, the external data are divided to rectangular parallelepiped cells that boundary planes intersect perpendicularly; by cell sorting means, the individual cells are sorted into boundary cells that include boundary data and non-boundary cells that do not include boundary data; by space sorting means, respective spaces are assigned to different space numbers where the cells are partitioned according to the boundary data; and by space number compression means, adjacent cells are reassigned to the same space numbers for cells that are not partitioned according to the boundary data.

Method and its program for cell labeling of volume data

A method of converting three-dimensional shape data into cell internal data. The method includes an oct-tree division step of dividing external data including boundary data of a target object into rectangular parallelepiped cells having boundary planes orthogonal to each other by oct-tree division. The method further includes a cell classification step of classifying each of the cells into an internal cell positioned inside or outside the target object or a boundary cell including the boundary data, and a cut point determination step of determining cut points of edges of the boundary cell based on the boundary data. The method further includes a boundary surface determination step of connecting cut points to form a polygon, and determining the polygon as the cell internal data when the number of the determined cut points is no fewer than 3 and no more than 12.

Method and program of converting three-dimensional shape data into cell internal data

A method and a program for converting boundary data into cell inner shape data, includes a division step (A) of dividing external data () constituted of the boundary data of an object into cells () in an orthogonal grid, a cutting point deciding step (B) of deciding an intersection point of the boundary data and a cell edge as a cell edge cutting point, a boundary deciding step (C) of deciding a boundary formed by connecting the cell edge cutting points as the cell inner shape data, a cell classification step (D) of classifying the divided cells into a nonboundary cell () including no boundary surface and a boundary cell () including a boundary surface, and a boundary cell data classification step (E) of classifying cell data constituting the boundary cell into internal cell data inside the cell inner shape data and external cell data outside the cell inner shape data.

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Wako, Japan

Yoshinori Teshima