公开(公告)号：JPH1040413A

公开(公告)日：1998-02-13

申请号：JP15461296

申请日：1996-06-14

Applicant: IBM

Inventor： OYAMADA KOJI

IPC: G06F17/50 ,  G06F17/17 ,  G06T15/08 ,  G06T17/00 ,  G06T15/00

Abstract: PROBLEM TO BE SOLVED: To provide a method for allocating volume data, which are defined at the center of a cell, to grid points while considering the residual. SOLUTION: Concerning the method for calculating the volume data at the plural grid points correspondently storing respective positions and ID from the volume data at the respective centers of plural cells composed of these plural grid points, the sum of values at points inside a certain cell found by interpolating the volume data at the respective grid points consisting of that cell and the residual as the difference of volume data at the center of this cell are weighted by a prescribed weight function. Then, the weighted residual is accumulated concerning all the areas of the cell, this accumulation is executed concerning all the cells, and the volume data at the respective grid points are found so that the collected results can be '0'.

公开(公告)号：JPH07200843A

公开(公告)日：1995-08-04

申请号：JP31674793

申请日：1993-12-16

Applicant: IBM

Inventor： ITO TAKAYUKI ,  OYAMADA KOJI

IPC: G06T11/20 ,  G06T15/08 ,  G06T17/00 ,  G06T11/00

Abstract: PURPOSE: To speedily generate an equal value surface for visualizing volume data. CONSTITUTION: This method generates the equal value surface formed by the set of grid points with a specific scalar value from volume data consisting of plural polyhedrons consisting of a prescribed number of grid points with a scalar value as visualized data. The method is provided with a pole extracting step for extracting grid points with a maximum or minimum scalar value among the grid points in volume data, a pole graph data preparing step for extracting information concerning a line segment combining between the grid points extracted as poles to store as pole graph data and an equal value surface generating step for generating the equal value surface concerning the scalar value designated by a user based on pole graph data.

公开(公告)号：JPH0636046A

公开(公告)日：1994-02-10

申请号：JP15990992

申请日：1992-06-19

Applicant: IBM

Inventor： OYAMADA KOJI ,  DOI AKIO ,  UNO SAKAE

IPC: G06T15/00 ,  G06T15/06 ,  G06T15/40 ,  G06F15/72

Abstract: PURPOSE: To eliminate the need of inspecting whether the line of sight crosses boundary by selecting the constitution face of a polyhedron, which makes the boundary of and area an faces in the direction of the line of sight and executing sorting based on a distance with the eyes. CONSTITUTION: A boundary face facing in the direction of the line of sight is sorted or the boundary face facing in the opposite direction to the line of sight is stored. Picture groups on a projection face, which correspond to the boundary face, are decided by a scan conversion 3 in a sorting order. A luminance value is calculated until a system goes out a volume data area along the eyes passing through them so as to decide the value of a picture element. When the volume data area is concave, the system once enters the volume data area again after it goes out the volume data area. Similar calculation is executed on the boundary of an entering position and it is accumulated in a previous value. Thus the precise luminance value can be calculated. It is not necessary to inspect whether the line of sight crosses the boundary or not only by using the scan version 3 in a boundary face unit.

公开(公告)号：JPH0816798A

公开(公告)日：1996-01-19

申请号：JP14601894

申请日：1994-06-28

Applicant: IBM

Inventor： OYAMADA KOJI ,  ITO TAKAYUKI

IPC: G06F17/50 ,  G06T7/00 ,  G06T11/20 ,  G06T17/20

Abstract: PURPOSE: To easily obtain the starting point of a stream line by using the result of finite element method analysis by calculating the starting point of the stream line moving from a singular point at an infinitesimal distance by each specific value, calculating the stream line from the starting point, and displaying it on a display. CONSTITUTION: Tetrahedral lattice data are collected (step 23), the data are the position data of the vertexes of each tetrahedral lattice and speed data at the points, and a singular point is calculated for each tetrahedron (step 25). However, there does not always exist any point with a speed 0 in the tetrahedron and when there is the singular point, Jacobian J is calculated, and an eigenvalue and an eigenvector are calculated (step 27). Then, when the speed is 0 at the singular point, stream line can not be drawn from that point, and a point separated from the singular point at an infinitesimal distance is defined as the starting point (step 29), and the stream line is calculated from this starting point, and displayed on a display or the like.

公开(公告)号：JPH0683978A

公开(公告)日：1994-03-25

申请号：JP350993

申请日：1993-01-12

Applicant: IBM

Inventor： GUREGORII POORU BARA ,  OYAMADA KOJI

IPC: G06F17/50 ,  G06F19/00 ,  G06T15/00 ,  G06T17/20 ,  G06T17/40 ,  G09B29/00 ,  G06F15/72

Abstract: PURPOSE: To provide a method which uses general hardware having a simple constitution to quickly generate equivalent surface picture data which can support a high-level interaction function. CONSTITUTION: This method generates an equivalent surface based on input data consisting of data expressing a set of points in a three-dimensioal space, connection state information related to this set, and data of a scalar field and is executed by an equivalent surface generator 103. This method includes a step where each of plural solid elements into which an object is divided is divided into a set of tetrahedrons so that faces of tetrahedron sub-elements of adjacent solid elements coincide with each other, a step where the range of the scalar field is divided into a prescribed number of stage values at regular intervals, a step where stage values included in each of tetrahedron sub-elements of the set of tetrahedrons of each solid element are discriminated, and a step where a set of equivalent facets corresponding to discriminated stage values is generated.

公开(公告)号：JPH0721405A

公开(公告)日：1995-01-24

申请号：JP14445993

申请日：1993-06-16

Applicant: IBM JAPAN

Inventor： MIYAZAWA TATSUO ,  DOI AKIO ,  OYAMADA KOJI

IPC: G06T15/08 ,  G06T15/00

Abstract: PURPOSE:To increase the value of a color on a part having large mirror reflection and to attain sufficient highlight expression by forming an object image whose opacity is increased based upon the size of a mirror reflection component. CONSTITUTION:Additional opacity alphas concerned and original opacity alphan are respectively led out from respective tables 11, 12 based upon the data value 17 of volume data 15, the value ¦N¦ 23 of a gradient vector is calculated and an adjusting function G concerned is led out from a table 13 based upon the value ¦N¦ 23. A previously found mirror reflection component 21 is multiplied by the additional opacity alphas the original opacity alphan is added to the multiplied value and the added result is multiplied by the function G to find out opacity alphai 24 emphasized at its sampling point. Thus color/opacity volume Cialphai constituted of the color value Ci of the found sampling point and the emphasized opacity alphai.

公开(公告)号：JPH03127188A

公开(公告)日：1991-05-30

申请号：JP26530989

申请日：1989-10-13

Applicant: IBM

Inventor： OYAMADA KOJI

IPC: G06T15/80 ,  G06T17/20

Abstract: PURPOSE: To directly generate shading picture data of a constant-height-surface without the aid of geometric data of a triangle by generating picture data of the constant-height-surface based on tetrahedral element representative normal vector data. CONSTITUTION: A space is virtually divided into a tetrahedral elements constituted with a point to which a scalar value is previously given as an apex. A list is generated and is stored in a storage device. Then, data of a vector (tetrahedral element representative normal vector) representing the normal vector of the constant-height-surface contained in the tetrahedral element is generated. Data of the normal vector (apex representative normal vector) related to the apex is generated and stored in the storage device based on the tetrahedral element representative normal vector data of the tetrahedral element including the apex for the respective apexes of the tetrahedral element. Picture data of the constant-height-surface having the designated scalar value is generated based on the stored list and apex representative normal vector data. Thus, the picture of the constant-height-surface can be generated at high speed without using multiple memories.