International Business Machines Corporation

Kazuya Shimizu

Masaki Aono

Hiroshi Minakata

Shigeru Kuriyama

Ryutarou Ohbuchi

Naoki Urano

The present invention is directed to a real-time controllable reflection mapping function which covers all stereoscopic directions of space. More specifically, the surface of a mirrored object is segmented into a plurality of polygonal elements (for example, triangles). Then, a polyhedron, which includes a predetermined point (for example, the center of the mirrored object) in a three-dimensional space (for example, a cube) in the interior thereof, is generated and a rendering process is performed for each surface of the polyhedron with the predetermined point as a view point. The rendered image is stored. Thereafter, a reflection vector is calculated between each vertex of the polygonal elements and a view point used when the entire three-dimensional space is rendered. Next, the surface of the polyhedron, in which an intersecting point between the reflection vector with the predetermined point as a start point and the polyhedron exists, is obtained. The coordinate in the image, which corresponds to each vertex of the polygonal elements, is calculated by using the surface where the intersecting point exists and the reflection vector. The image is texture-mapped onto the surface of the object by using the coordinate in the image which corresponds to each vertex of the polygonal elements. Finally, the result of the texture mapping is displayed.

Rendering method and apparatus

A method for generating a multisided patch in which the expression form of each boundary curve and topology of the curve network can freely be set, curve formulae can be simply input, and high continuity. By inputting data of boundary curves to multisided patch generator via editing means which generates and edits curves, and blending sweep surfaces in two stages, a free-form surface is generated as a surface interpolating them. That is, data of a plurality of boundary curves is inputted to multisided patch generator, each given curve is swept by sweeping means along the curves intersecting it to generate surfaces, and the surfaces are blended by blending means in two stages, thereby generating a free-form surface. Since the surface formulae can be defined on the basis of the curve formulae of the boundaries, topology of the curve network and the descriptive form of each curve can freely be set, so that the boundary curve formulae of a multisided patch can be simply input by directly drawing the curve shapes on defined two-dimensional planes. In addition, geometric continuity of the generated surface is high because continuity of the given curves is high.

Growing community of inventors

Chiba-ken, Japan

Kazuya Shimizu