公开(公告)号：JPH05135138A

公开(公告)日：1993-06-01

申请号：JP31858291

申请日：1991-11-07

Applicant: IBM

Inventor： KURIYAMA SHIGERU ,  NAMIKATA HIROSHI ,  URANO NAOKI ,  SHIMIZU KAZUYA

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

Abstract: PURPOSE: To attain the simple input of a curve expression, and to generate a polygonal patch having high continuity by generating a curved surface interpolating a curve by fusing a curve sweeping body across two stages. CONSTITUTION: This device is provided with a polygonal patch generator 8 which generates a curved surface expression based on a curve expression inputted from a coordinate inputting device and a multivariate coordinate inputted from an inputting device 3, and outputs it as polygonal patch data. Then, the data of a boundary curve are inputted through an editing means 4 which operates the generation and edition of the curve to the polygonal patch generator 8, and a free curved surface is generated as a curved surface interpolating each by fusing a curve sweeping body across two stages. That is, the data of the plural boundary curves are inputted to the polygonal patch generator 8, the curved surface is generated by sweeping each applied curve along the curve crossing the data by a sweeping means 23, and the curved surface is fused across two stages by fusing means 24 and 26 so that the free curved surface can be generated. The expression for the curved surface is defined based on the expression for the boundary of the curve.

公开(公告)号：JPH10105734A

公开(公告)日：1998-04-24

申请号：JP23000596

申请日：1996-08-30

Applicant: IBM

Inventor： AONO MASAKI ,  OBUCHI RYUTARO ,  SHIMIZU KAZUYA

IPC: G06T15/00 ,  G06T15/04

Abstract: PROBLEM TO BE SOLVED: To provide a reflection mapping function which covers all three- dimensional directions of a space and can be controlled in real time. SOLUTION: The surface of an object having a specular surface is divided into plural polygonal elements (for example, triangles). A polyhedron (for example, a cube) which internally has a prescribed point (for example, the center of the object having the specular surface) in a three-dimensional space is generated, and each surface if the polyhedron is subjected to rendering processing with the prescribed point as the view point, and a generated picture is stored. Thereafter, a reflection vector at each apex of polygonal elements is obtained from a view point for rendering of the whole of the three-dimensional space. The surface where an intersection between a reflection vector having the prescribed point as the start point and the polyhedron exists is obtained, and this surface where the intersection exists and reflection vectors are used to obtain coordinates in the stored picture which correspond to respective apexes of polygonal elements. They are used to perform texture mapping of the picture on the surface of the object having the specular surface. Finally, the result of texture mapping is displayed to terminate the processing.