Zoë Dowling, University of Surrey Kristin Stettler, US Census Bureau
Presented By Greg Gire Advised By Zoë Wood California Polytechnic State University.
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Transcript of Presented By Greg Gire Advised By Zoë Wood California Polytechnic State University.
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Presented ByGreg Gire
Advised By Zoë Wood
California Polytechnic State University
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Introduction Problem
Simplifying Polygonal Meshes History Metrics
Normal Mapping History Metrics
My Thesis
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3D Models represented as mesh of polygons
http://www.pixolator.com/zbc/attachment.php?attachmentid=15162
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What is the optimal simplified mesh to apply appearance preservation to make it appear the most visually similar to the original mesh?
558 quads
65 quads
225,467 quads
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My thesis will focus on generating the best simplified mesh that will be most visually similar to the original high resolution mesh
43,850 quads
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Problem: Rendering complex meshes requires a
large amount of memory, processing power, and time
This is bad for interactive graphics applications such as animation and video games
Solution: Reduce the level of detail (polygon count)
while maintaining its overall shape
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Triangle Decimation Schroeder et al. 1992
Multiple passes over mesh to remove vertices that meet decimation criteria; patch hole
http://www.emeraldinsight.com/fig/1560020102012.png
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Re-tiling Greg Turk 1992
Create new vertices that approximate the curvature of a model; re-triangulate
[Turk 1992]
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Progressive Meshes Hughes Hoppe 1996
Iterative collapse of an edge into a single vertex; stores collapses to adjust LOD
[Hoppe 1996]
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Quadric Error Metrics Garland and Heckbert 1997
Collapse two vertices into one; use of quadrics to approximate cost of collapse
[Garland and Heckbert 1997]
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Metrics Geometric similarity▪ Topology
Time Space
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Problem: Simplified meshes may
work for animation, but not so good for video games
Solution: Preserve appearance from
complex mesh and “paint” it on simplified mesh using existing graphics hardware
http://www.webreference.com/3d/lesson57/57-1.jpg
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Displacement mapping Krishnamurthy et al. 1996
User defines patches that approximate surface; stores distance for displacement
[Krishnamurthy et al. 1996]
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Normal mapping Cignoni et al.
1998Sample
complex mesh and store normals into texture image
[Cignoni et al. 1998]
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Metrics Visual similarity Time Space
http://ja.gram.pl/upl/blogi/264034/img_wpisy/2008_05/postacie.jpg
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The combination of simplification and appearance preserving algorithms allows detailed models in drastically less time
http://upload.wikimedia.org/wikipedia/commons/3/36/Normal_map_example.png
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Problem: There are many
techniques and levels of detail for model simplification, and not all look equal when a normal map is applied
Solution: Optimize simplified mesh
for normal mapping
[Garland and Heckbert 1997]
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My Thesis1) Add visual similarity metric to QEM
simplification2) Generate normal maps using MELODY3) Compare visual similarity of high
resolution mesh to optimized mesh and other simplified meshes
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CIGNONI, P., MONTANI, C., ROCCHINI, C., AND SCOPIGNO, R. 1998. A general method for preserving attribute values on simplified meshes. In Visualization '98. Proceedings, 1998, 59-66.
COHEN, J., OLANO, M., AND MANOCHA, D. 1998. Appearance-preserving simplification. In Proceedings of the 25th annual conference on Computer graphics and interactive techniques, 1998, ACM, , 115-122.
SCHROEDER, W.J., ZARGE, J.A., AND LORENSEN, W.E. 1992. Decimation of triangle meshes. In Proceedings of the 19th annual conference on Computer graphics and interactive techniques, 1992, ACM, , 65-70.
KRISHNAMURTHY, V. AND LEVOY, M. 1996. Fitting smooth surfaces to dense polygon meshes. In Proceedings of the 23rd annual conference on Computer graphics and interactive techniques, 1996, ACM, , 313-324.
RONFARD, R. AND ROSSIGNAC, J. 1996. Full-range approximation of triangulated polyhedra. Computer Graphics Forum 15, 67-76.
CLARK, J.H. 1976. Hierarchical geometric models for visible surface algorithms. Commun. ACM 19, 547-554.
HOPPE, H., DEROSE, T., DUCHAMP, T., MCDONALD, J., AND STUETZLE, W. 1993. Mesh optimization. In Proceedings of the 20th annual conference on Computer graphics and interactive techniques, Anaheim, CA, 1993, ACM, Anaheim, CA, 19-26.
HOPPE, H. 1996. Progressive meshes. In Proceedings of the 23rd annual conference on Computer graphics and interactive techniques, 1996, ACM, , 99-108.
WILLIAMS, L. 1983. Pyramidal parametrics. In Proceedings of the 10th annual conference on Computer graphics and interactive techniques, Detroit, Michigan, United States, 1983, ACM, Detroit, Michigan, United States, 1-11.
TURK, G. 1992. Re-tiling polygonal surfaces. In Proceedings of the 19th annual conference on Computer graphics and interactive techniques, 1992, ACM, , 55-64.
REDDY, M. 1996. SCROOGE:Perceptually-Driven Polygon Reduction. Computer Graphics Forum 15, 191-203.
COHEN, J., VARSHNEY, A., MANOCHA, D., TURK, G., WEBER, H., AGARWAL, P., BROOKS, F., AND WRIGHT, W. 1996. Simplification envelopes. In Proceedings of the 23rd annual conference on Computer graphics and interactive techniques, 1996, ACM, , 119-128.
GARLAND, M. AND HECKBERT, P.S. 1997. Surface simplification using quadric error metrics. In Proceedings of the 24th annual conference on Computer graphics and interactive techniques, 1997, ACM Press/Addison-Wesley Publishing Co., , 209-216.
HECKBERT, P. 1986. Survey of Texture Mapping. Computer Graphics and Applications, IEEE 6, 56-67.
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