Patent US6034691A successfully refreshed from Google Patents.
US6034691A
Expired / Lapsed
US
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Rendering method and apparatus
Assignee: Google LLC
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Filing: 1997-07-29
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Granted: 2000-03-07
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Expires: 2017-07-29
Abstract
Abstract 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.
Inventors
- 👤 Masaki Aono
- 👤 Ryutarou Ohbuchi
- 👤 Kazuya Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:02
CPC Classifications
G; G06; G06T; G06T15/00; G06T15/10
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
311 words
A method for rendering a three-dimensional space which includes an object with a mirror, comprising the steps of: segmenting the surface of said object into a plurality of polygonal elements; generating a polyhedron which includes a predetermined point in said three-dimensional space in the interior thereof, performing a rendering process for each surface of said polyhedron with said predetermined point as a view point, and storing rendered image; calculating a reflection vector at each vertex of said polygonal elements from a view point used when the entire three-dimensional space is rendered; identifying a surface of said polyhedron in which an intersecting point between said reflection vector with said predetermined point as a start point and said polyhedron exists, checking whether the surfaces where said intersecting point exists are all identical for each vertex of one polygonal element; and if all of said surfaces are identical, calculating a coordinate in said rendered image which corresponds to each vertex of said polygonal elements by using said surface where said intersecting point exists and said reflection vector; and if all of said surfaces are not identical, clipping said polyhedron by a polygonal pyramid whose apex is said predetermined point and whose ridgeline is said reflection vector of each vertex of said one polygonal element, and calculating a reflection vector on a boundary line of each surface of said polyhedron; calculating a coordinate in said rendered image, which corresponds to said reflection vector on said boundary line, from said reflection vector on said boundary line; and calculating a point on said object which corresponds to said reflection vector on said boundary line; and performing a texture-mapping of said rendered image onto said surface of said object by using said coordinate in said rendered image which corresponds to each vertex of said polygonal elements and a calculated point; and displaying a result of the texture mapping.
Claim 2
Independent Claim
311 words
A method for rendering a three-dimensional space which includes an object with a mirror, comprising the steps of: segmenting the surface of said object into a plurality of polygonal elements; generating a polyhedron which includes a predetermined point in said three-dimensional space in the interior thereof, performing a rendering process for each surface of said polyhedron with said predetermined point as a view point, and storing rendered image; calculating a reflection vector at each vertex of said polygonal elements from a view point used when the entire three-dimensional space is rendered; identifying a surface of said polyhedron in which an intersecting point between said reflection vector with said predetermined point as a start point and said polyhedron exists, checking whether the surfaces where said intersecting point exists are all identical for each vertex of one polygonal element; and if all of said surfaces are identical, calculating a coordinate in said rendered image which corresponds to each vertex of said polygonal elements by using said surface where said intersecting point exists and said reflection vector; and if all of said surfaces are not identical, clipping said polyhedron by a polygonal pyramid whose apex is said predetermined point and whose ridgeline is said reflection vector of each vertex of said one polygonal element, and calculating a reflection vector on a boundary line of each surface of said polyhedron; calculating a coordinate in said rendered image, which corresponds to said reflection vector on said boundary line, from said reflection vector on said boundary line; and calculating a point on said object which corresponds to said reflection vector on said boundary line; and performing a texture-mapping of said rendered image onto said surface of said object by using said coordinate in said rendered image which corresponds to each vertex of said polygonal elements and a calculated point; and displaying a result of the texture mapping.
Claim 3
Dependent Claim
26 words
The method according to claim 1, wherein the images, generated for surfaces of said polyhedron by said rendering process, are stored as a sheet of image.
Claim 4
Dependent Claim
70 words
The method according to claim 1, wherein said step of calculating a point on said object includes a step of calculating the point on said object by internally dividing, from a ratio of angles formed by said reflection vector on said boundary line and two reflection vectors employed when said reflection vector on said boundary line is calculated, two points on said object which correspond to said two reflection vectors.
Claim 5
Dependent Claim
131 words
The method according to claim 1, wherein said step of calculating a point on said object includes the steps of: calculating a reflection vector at the middle point between the two points on said object which correspond to two reflection vectors employed when the reflection vector on said boundary line is calculated; judging whether a difference between the reflection vector at said middle point and the reflection vector on said boundary line is less than a predetermined value; and when the difference is not less than the predetermined value, executing the step of calculating a reflection vector at said middle point and subsequent steps by using said middle point and either of said two points as said two points in the step of calculating a reflection vector at said middle point.
Claim 6
Dependent Claim
46 words
The method according to claim 3, further comprising the steps of: judging whether a difference between reflection vectors at the vertices of a certain polygonal element is greater than a threshold value; and if the difference is greater than said threshold, subdividing said certain polygonal element.
Claim 7
Dependent Claim
12 words
The method according to claim 3, wherein said polygon is a triangle.
Claim 8
Dependent Claim
12 words
The method according to claim 3, wherein said polyhedron is a cube.
Claim 9
Dependent Claim
26 words
The apparatus according to claim 7, wherein the images, generated for surfaces of said polyhedron by said rendering process, are stored as a sheet of image.
Claim 10
Independent Claim
349 words
An apparatus for rendering a three-dimensional space which includes an object with a mirror, comprising a mesher for segmenting the surface of said object into a plurality of polygonal elements; a reflection map generator for generating a polyhedron which includes a predetermined point in said three-dimensional space in the interior thereof and for performing a rendering process for each surface of said polyhedron with said predetermined point as a view point and for storing the rendered image; means for calculating a reflection vector at each vertex of said polygonal elements from a view point used when the entire three-dimensional space is rendered; a coordinate generator for identifying a surface of said polyhedron in which an intersecting point between said reflection vector with said predetermined point as a start point and said polyhedron exists, said coordinate generator means including means for checking whether the surfaces where said intersecting point exists are all identical for each vertex of one polygonal element; and if all of said surfaces are identical, said coordinate generator calculating a coordinate in said rendered image which corresponds to each vertex of said polygonal elements by using said surface where said intersecting point exists and said reflection vector; means for clipping said polyhedron by a polygonal pyramid whose apex is said predetermined point and whose ridgeline is said reflection vector of each vertex of said one polygonal element and for calculating a reflection vector on a boundary line of each surface of said polyhedron, if all of said surfaces are not identical; means for calculating a coordinate in said rendered image, which corresponds to said reflection vector on said boundary line, from said reflection vector on said boundary line; means for calculating a point on said object which corresponds to said reflection vector on said boundary lines; a texture mapping processor for performing a texture mapping of said rendered image onto said surface of said object by using said coordinate in said rendered image which corresponds to each vertex of said polygonal elements and a calculated point; and a display for displaying a result of the texture mapping.
Claim 11
Independent Claim
349 words
An apparatus for rendering a three-dimensional space which includes an object with a mirror, comprising a mesher for segmenting the surface of said object into a plurality of polygonal elements; a reflection map generator for generating a polyhedron which includes a predetermined point in said three-dimensional space in the interior thereof and for performing a rendering process for each surface of said polyhedron with said predetermined point as a view point and for storing the rendered image; means for calculating a reflection vector at each vertex of said polygonal elements from a view point used when the entire three-dimensional space is rendered; a coordinate generator for identifying a surface of said polyhedron in which an intersecting point between said reflection vector with said predetermined point as a start point and said polyhedron exists, said coordinate generator means including means for checking whether the surfaces where said intersecting point exists are all identical for each vertex of one polygonal element; and if all of said surfaces are identical, said coordinate generator calculating a coordinate in said rendered image which corresponds to each vertex of said polygonal elements by using said surface where said intersecting point exists and said reflection vector; means for clipping said polyhedron by a polygonal pyramid whose apex is said predetermined point and whose ridgeline is said reflection vector of each vertex of said one polygonal element and for calculating a reflection vector on a boundary line of each surface of said polyhedron, if all of said surfaces are not identical; means for calculating a coordinate in said rendered image, which corresponds to said reflection vector on said boundary line, from said reflection vector on said boundary line; means for calculating a point on said object which corresponds to said reflection vector on said boundary lines; a texture mapping processor for performing a texture mapping of said rendered image onto said surface of said object by using said coordinate in said rendered image which corresponds to each vertex of said polygonal elements and a calculated point; and a display for displaying a result of the texture mapping.
Claim 12
Dependent Claim
69 words
The apparatus according to claim 9, wherein said means for calculating a point on said object includes means for calculating the point on said object by internally dividing, from a ratio of angles formed by said reflection vector on said boundary line and two reflection vectors employed when said reflection vector on said boundary line is calculated, two points on said object which correspond to said two reflection vectors.
Claim 13
Dependent Claim
131 words
The apparatus according to claim 9, wherein said means for calculating a point on said object includes: means for calculating a reflection vector at the middle point between the two points on said object which correspond to two reflection vectors employed when the reflection vector on said boundary line is calculated; and means for judging whether a difference between the reflection vector on said middle point and the reflection vector on said boundary line is less than a predetermined value, and if the difference is not less than the predetermined value, for instructing the means for calculating a reflection vector at said middle point by using said middle point and either of said two points as said two point in said means for calculating a reflection vector at said middle point.
Claim 14
Dependent Claim
51 words
The apparatus according to claim 11, further comprising: a judging unit for judging whether a difference between reflection vectors at the vertices of a certain polygonal element is greater than a threshold value; and an adaptive mesher for subdividing said certain polygonal element if the difference is greater than said threshold.
Claim 15
Dependent Claim
308 words
A mirrored object rendering program for causing a computer to render a three-dimensional space which includes an object with a mirror, comprising the steps of: when a plurality of polygonal elements obtained by segmenting the surface of said object, a polyhedron which includes a predetermined point in said three-dimensional space in the interior thereof, and an image generated by performing a rendering process for each surface of said polyhedron with said predetermined point as a view point are prepared; causing said computer to calculate a reflection vector at each vertex of said polygonal elements from a view point used when the entire three-dimensional space is rendered; causing said computer to identify a surface of said polyhedron in which an intersecting point between said reflection vector with said predetermined point as a start point and said polyhedron exists causing said computer to check whether the surfaces where said intersecting point exists are all identical for each vertex of one polygonal element; and if all of said surfaces are identical, causing said computer to calculate a coordinate in said rendered image which corresponds to each vertex of said polygonal elements by using said surface where said intersecting point exists and said reflection vector; and, if all of said surface are not identical, causing said computer to clip said polyhedron by a polygonal pyramid whose apex is said predetermined point and whose ridgeline is said reflection vector of each vertex of said one polygonal element, and to calculate a reflection vector on a boundary line of each surface of said polyhedron; causing said computer to calculate a coordinate in said rendered image, which corresponds to said reflection vector on said boundary line, from said reflection vector on said boundary line; and causing said computer to calculate a point on said object which corresponds to said reflection vector on said boundary line.
Claim 16
Dependent Claim
308 words
A mirrored object rendering program for causing a computer to render a three-dimensional space which includes an object with a mirror, comprising the steps of: when a plurality of polygonal elements obtained by segmenting the surface of said object, a polyhedron which includes a predetermined point in said three-dimensional space in the interior thereof, and an image generated by performing a rendering process for each surface of said polyhedron with said predetermined point as a view point are prepared; causing said computer to calculate a reflection vector at each vertex of said polygonal elements from a view point used when the entire three-dimensional space is rendered; causing said computer to identify a surface of said polyhedron in which an intersecting point between said reflection vector with said predetermined point as a start point and said polyhedron exists causing said computer to check whether the surfaces where said intersecting point exists are all identical for each vertex of one polygonal element; and if all of said surfaces are identical, causing said computer to calculate a coordinate in said rendered image which corresponds to each vertex of said polygonal elements by using said surface where said intersecting point exists and said reflection vector; and, if all of said surface are not identical, causing said computer to clip said polyhedron by a polygonal pyramid whose apex is said predetermined point and whose ridgeline is said reflection vector of each vertex of said one polygonal element, and to calculate a reflection vector on a boundary line of each surface of said polyhedron; causing said computer to calculate a coordinate in said rendered image, which corresponds to said reflection vector on said boundary line, from said reflection vector on said boundary line; and causing said computer to calculate a point on said object which corresponds to said reflection vector on said boundary line.
Claim 17
Dependent Claim
76 words
The program according to claim 13, wherein said step of causing to calculate a point on said object includes a step of causing said computer to calculate the point on said object by internally dividing, from a ratio of angles formed by said reflection vector on said boundary line and two reflection vectors employed when said reflection vector on said boundary line is calculated, two points on said object which correspond to said two reflection vectors.
Claim 18
Dependent Claim
143 words
The program according to claim 13, wherein said step of causing to calculate a point on said object includes: causing said computer to calculate a reflection vector at the middle point between the two points on said object which correspond to two reflection vectors employed when the reflection vector on said boundary line is calculated; causing said computer to judge whether a difference between the reflection vector at said middle point and the reflection vector on said boundary line is less than a predetermined value; and if the difference is not less than the predetermined value, causing said computer to execute the step of calculating a reflection vector at said middle point and subsequent steps by using said middle point and either of said two points as said two points in said step of causing calculate a reflection vector at said middle point.
Claim 19
Dependent Claim
54 words
The program according to claim 13, further comprising the steps of: causing said computer to judge whether a difference between reflection vectors at the vertices of a certain polygonal element is greater than a threshold value; and causing said computer to subdivide said certain polygonal element if the difference is greater than said threshold.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-03-07 | 2003-09-06 | 2004-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-03-07 | 2007-09-06 | 2008-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-03-07 | 2011-09-06 | 2012-03-07 | $7700.00 | Window Closed / Lapsed |