US 7,321,366 B2
Method and program for converting boundary data into cell inner shape data
Yoshinori Teshima, Wako (Japan); Kiwamu Kase, Wako (Japan); Shugo Usami, Wako (Japan); and Akitake Makinouchi, Wako (Japan)
Assigned to Riken, Saitama (Japan)
Appl. No. 10/505,224
PCT Filed Feb. 27, 2003, PCT No. PCT/JP03/02197
§ 371(c)(1), (2), (4) Date Aug. 20, 2004,
PCT Pub. No. WO03/073335, PCT Pub. Date Sep. 04, 2003.
Claims priority of application No. 2002-053575 (JP), filed on Feb. 28, 2002.
Prior Publication US 2005/0216238 A1, Sep. 29, 2005
Int. Cl. G06T 17/00 (2006.01)
U.S. Cl. 345—424 18 Claims
OG exemplary drawing
 
1. A method for converting boundary data into cell inner shape data, comprising:
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;
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; and
step (F) of outputting the cell inner shape data to a display, wherein the cells are rectangular cells in two-dimensional representation, and
in the cutting point deciding step (B), intersection points of boundary data and cell edges that have totally 24=16 arrangement cases are decided as the cell edge cutting points, and the arrangement cases that become equivalence classes by rotational operation are decided as identical patterns so that the 24=16 arrangement cases are further classified into 6 patterns, and
in the cutting point deciding step (B), as for arrangement of each intersection point, data concerning the rotational operation and data concerning the identical pattern are stored in a storage device, wherein
in the boundary deciding step (C), a boundary line made by connecting the cell edge cutting points is decided as the cell inner shape data for all the 6 patterns.