Riken Corporation

Shugo Usami

Kiwamu Kase

Yoshinori Teshima

Akitake Makinouchi

Shuntaro Yamazaki

Hiroshi Yagi

Masaya Kato

Yu-ichiro Terada

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 data input means inputs boundary data of an object to a computer, a data converting means converts the boundary data into a triangle patch having a phase, an associating means divides a space into rectangular parallelepiped cells having boundary planes intersecting perpendicularly and associates the cell with a triangle to be included in the cell, a dividing/arranging means divides a triangle patch having a phase and floating in the space at cell faces and keeps all triangles arranged within and on the boundaries of cells, a ridge line integrating means integrates ridges that do not alter the phase, a cell assigning means assigns each triangle and its vertex to a cell with reference to index data of the vertex, and a labeling means sets an attribute value of each cell.

Method and program for generating volume data from boundary representation 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.

A coordinate system R is set in which Pis a coordinate origin, PPconforms to a first U axis to have a unit length, PPconforms to a second V axis to have a unit length, and PP&#xd7;PPis a unit vector conforming to a third N axis. A transforming matrix M that transforms an ordinary coordinate system into the coordinate system R and the u-, v- and n-coordinate values of the both ends of the line segment are calculated. It is determined whether or not the line segment intersects with the triangle, on the basis of the u-, v- and n-coordinate values. The u-, and v-coordinate values of the intersection point are calculated. It is determined whether or not the intersection point is positioned inside the triangle, on the basis of the u-, and v-coordinate values of the intersection point.

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Saitama, Japan

Shugo Usami