3D graphics eBook - Course Materials Repository
3D graphics eBook - Course Materials Repository 3D graphics eBook - Course Materials Repository
Potentially visible set 113 Secondary Problems Some interesting secondary problems include: [7] [11] [12] • Compute an optimal sub-division in order to maximize visibility culling. • Compress the visible set data in order to minimize storage overhead. [13] Implementation Variants • It is often undesirable or inefficient to simply compute triangle level visibility. Graphics hardware prefers objects to be static and remain in video memory. Therefore, it is generally better to compute visibility on a per-object basis and to sub-divide any objects that may be too large individually. This adds conservativity, but the benefit is better hardware utilization and compression (since visibility data is now per-object, rather than per-triangle). • Computing cell or sector visibility is also advantageous, since by determining visible regions of space, rather than visible objects, it is possible to not only cull out static objects in those regions, but dynamic objects as well. References [1] S. Nirenstein, E. Blake, and J. Gain. Exact from-region visibility culling (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 131. 7204), In Proceedings of the 13th workshop on Rendering, pages 191–202. Eurographics Association, June 2002. [2] Daniel Cohen-Or, Yiorgos Chrysanthou, Cl´audio T. Silva, and Fr´edo Durand. A survey of visibility for walkthrough applications (http:/ / citeseer. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 148. 4589), IEEE TVCG, 9(3):412–431, July-September 2003. [3] 3D Visibility: Analytical study and Applications (http:/ / people. csail. mit. edu/ fredo/ THESE/ ), Frédo Durand, PhD thesis, Université Joseph Fourier, Grenoble, France, July 1999. is strongly related to exact visibility computations. [4] Shaun Nirenstein and Edwin Blake, Hardware Accelerated Visibility Preprocessing using Adaptive Sampling (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 64. 3231), Rendering Techniques 2004: Proceedings of the 15th Eurographics Symposium on Rendering, 207- 216, Norrköping, Sweden, June 2004. [5] Peter Wonka, Michael Wimmer, Kaichi Zhou, Stefan Maierhofer, Gerd Hesina, Alexander Reshetov. Guided Visibility Sampling (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 91. 5278), ACM Transactions on Graphics. volume 25. number 3. pages 494 - 502. 2006. Proceedings of SIGGRAPH 2006. [6] Craig Gotsman, Oded Sudarsky, and Jeffrey A. Fayman. Optimized occlusion culling using five-dimensional subdivision (http:/ / www. cs. technion. ac. il/ ~gotsman/ AmendedPubl/ OptimizedOcclusion/ optimizedOcclusion. pdf), Computers & Graphics, 23(5):645–654, October 1999. [7] Seth Teller, Visibility Computations in Densely Occluded Polyhedral Environments (http:/ / www. eecs. berkeley. edu/ Pubs/ TechRpts/ 1992/ CSD-92-708. pdf) (Ph.D. dissertation, Berkeley, 1992) [8] Jiri Bittner. Hierarchical Techniques for Visibility Computations (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 2. 9886), PhD Dissertation. Department of Computer Science and Engineering. Czech Technical University in Prague. Submitted October 2002, defended March 2003. [9] Denis Haumont, Otso Mäkinen and Shaun Nirenstein, A low Dimensional Framework for Exact Polygon-to-Polygon Occlusion Queries (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 66. 6371), Rendering Techniques 2005: Proceedings of the 16th Eurographics Symposium on Rendering, 211-222, Konstanz, Germany, June 2005 [10] Jiri Bittner, Peter Wonka, Michael Wimmer. Fast Exact From-Region Visibility in Urban Scenes (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 71. 3271), In Proceedings of Eurographics Symposium on Rendering 2005, pages 223-230. [11] D. Haumont, O. Debeir and F. Sillion, Graphics Forum, Volumetric Cell-and-Portal Generation (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 163. 6834), Volume 22, Number 3, pages 303-312, September 2003 [12] Oliver Mattausch, Jiri Bittner, Michael Wimmer, Adaptive Visibility-Driven View Cell Construction (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 67. 6705), In Proceedings of Eurographics Symposium on Rendering 2006. [13] Michiel van de Panne and A. James Stewart, Effective Compression Techniques for Precomputed Visibility (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 116. 8940), Eurographics Workshop on Rendering, 1999, pg. 305-316, June.
Potentially visible set 114 External links Cited author's pages (including publications): • Jiri Bittner (http:/ / www. cgg. cvut. cz/ ~bittner/ ) • Daniel Cohen-Or (http:/ / www. math. tau. ac. il/ ~dcor/ ) • Fredo Durand (http:/ / people. csail. mit. edu/ fredo/ ) • Denis Haumont (http:/ / www. ulb. ac. be/ polytech/ sln/ team/ dhaumont/ dhaumont. html) • Shaun Nirenstein (http:/ / www. nirenstein. com) • Seth Teller (http:/ / people. csail. mit. edu/ seth/ ) • Peter Wonka (http:/ / www. public. asu. edu/ ~pwonka/ ) Other links: • Selected publications on visibility (http:/ / artis. imag. fr/ ~Xavier. Decoret/ bib/ visibility/ ) Precomputed Radiance Transfer Precomputed Radiance Transfer (PRT) is a computer graphics technique used to render a scene in real time with complex light interactions being precomputed to save time. Radiosity methods can be used to determine the diffuse lighting of the scene, however PRT offers a method to dynamically change the lighting environment. In essence, PRT computes the illumination of a point as a linear combination of incident irradiance. An efficient method must be used to encode this data, such as Spherical harmonics. When spherical harmonics is used to approximate the light transport function, only low frequency effect can be handled with a reasonable number of parameters. Ren Ng extended this work to handle higher frequency shadows by replacing spherical harmonics with non-linear wavelets. Teemu Mäki-Patola gives a clear introduction to the topic based on the work of Peter-Pike Sloan et al. [1] At SIGGRAPH 2005, a detailed course on PRT was given. [2] References [1] Teemu Mäki-Patola (2003-05-05). "Precomputed Radiance Transfer" (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 131. 6778) (PDF). Helsinki University of Technology. . Retrieved 2008-02-25. [2] Jan Kautz; Peter-Pike Sloan, Jaakko Lehtinen. "Precomputed Radiance Transfer: Theory and Practice" (http:/ / www. cs. ucl. ac. uk/ staff/ j. kautz/ PRTCourse/ ). SIGGRAPH 2005 Courses. . Retrieved 2009-02-25. • Peter-Pike Sloan, Jan Kautz, and John Snyder. "Precomputed Radiance Transfer for Real-Time Rendering in Dynamic, Low-Frequency Lighting Environments". ACM Transactions on Graphics, Proceedings of the 29th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH), pp. 527-536. New York, NY: ACM Press, 2002. (http:/ / www. mpi-inf. mpg. de/ ~jnkautz/ projects/ prt/ prtSIG02. pdf) • NG, R., RAMAMOORTHI, R., AND HANRAHAN, P. 2003. All-Frequency Shadows Using Non-Linear Wavelet Lighting Approximation. ACM Transactions on Graphics 22, 3, 376–381. (http:/ / graphics. stanford. edu/ papers/ allfreq/ allfreq. press. pdf)
- Page 67 and 68: High dynamic range rendering 62 Fro
- Page 69 and 70: High dynamic range rendering 64 •
- Page 71 and 72: Irregular Z-buffer 66 Applications
- Page 73 and 74: Lambert's cosine law 68 than would
- Page 75 and 76: Lambertian reflectance 70 Lambertia
- Page 77 and 78: Level of detail 72 Well known appro
- Page 79 and 80: Level of detail 74 Hierarchical LOD
- Page 81 and 82: Newell's algorithm 76 Newell's algo
- Page 83 and 84: Non-uniform rational B-spline 78 Us
- Page 85 and 86: Non-uniform rational B-spline 80 of
- Page 87 and 88: Non-uniform rational B-spline 82 ar
- Page 89 and 90: Non-uniform rational B-spline 84 Ex
- Page 91 and 92: Normal mapping 86 How it works To c
- Page 93 and 94: OrenNayar reflectance model 88 Oren
- Page 95 and 96: OrenNayar reflectance model 90 , ,
- Page 97 and 98: Painter's algorithm 92 The algorith
- Page 99 and 100: Parallax mapping 94 • Parallax Ma
- Page 101 and 102: Particle system 96 A cube emitting
- Page 103 and 104: Path tracing 98 History Further inf
- Page 105 and 106: Path tracing 100 Scattering distrib
- Page 107 and 108: Phong reflection model 102 Visual i
- Page 109 and 110: Phong reflection model 104 Because
- Page 111 and 112: Phong shading 106 Visual illustrati
- Page 113 and 114: Photon mapping 108 Rendering (2nd p
- Page 115 and 116: Photon tracing 110 Advantages and d
- Page 117: Potentially visible set 112 • Can
- Page 121 and 122: Procedural generation 116 increases
- Page 123 and 124: Procedural generation 118 • Softi
- Page 125 and 126: Procedural generation 120 Reference
- Page 127 and 128: Procedural texture 122 Self-organiz
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- Page 131 and 132: 3D projection 126 The distance of t
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- Page 145 and 146: Radiosity 140 Overview of the radio
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- Page 149 and 150: Radiosity 144 References [1] " Mode
- Page 151 and 152: Ray casting 146 the light will reac
- Page 153 and 154: Ray tracing 148 Typically, each ray
- Page 155 and 156: Ray tracing 150 independence of eac
- Page 157 and 158: Ray tracing 152 On June 12, 2008 In
- Page 159 and 160: Reflection 154 Reflection Reflectio
- Page 161 and 162: Reflection 156 Glossy Reflection Fu
- Page 163 and 164: Reflection mapping 158 Cube mapping
- Page 165 and 166: Render Output unit 160 Render Outpu
- Page 167 and 168: Rendering 162 • indirect illumina
Potentially visible set 113<br />
Secondary Problems<br />
Some interesting secondary problems include:<br />
[7] [11] [12]<br />
• Compute an optimal sub-division in order to maximize visibility culling.<br />
• Compress the visible set data in order to minimize storage overhead. [13]<br />
Implementation Variants<br />
• It is often undesirable or inefficient to simply compute triangle level visibility. Graphics hardware prefers objects<br />
to be static and remain in video memory. Therefore, it is generally better to compute visibility on a per-object<br />
basis and to sub-divide any objects that may be too large individually. This adds conservativity, but the benefit is<br />
better hardware utilization and compression (since visibility data is now per-object, rather than per-triangle).<br />
• Computing cell or sector visibility is also advantageous, since by determining visible regions of space, rather than<br />
visible objects, it is possible to not only cull out static objects in those regions, but dynamic objects as well.<br />
References<br />
[1] S. Nirenstein, E. Blake, and J. Gain. Exact from-region visibility culling (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 131.<br />
7204), In Proceedings of the 13th workshop on Rendering, pages 191–202. Euro<strong>graphics</strong> Association, June 2002.<br />
[2] Daniel Cohen-Or, Yiorgos Chrysanthou, Cl´audio T. Silva, and Fr´edo Durand. A survey of visibility for walkthrough applications (http:/ /<br />
citeseer. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 148. 4589), IEEE TVCG, 9(3):412–431, July-September 2003.<br />
[3] <strong>3D</strong> Visibility: Analytical study and Applications (http:/ / people. csail. mit. edu/ fredo/ THESE/ ), Frédo Durand, PhD thesis, Université<br />
Joseph Fourier, Grenoble, France, July 1999. is strongly related to exact visibility computations.<br />
[4] Shaun Nirenstein and Edwin Blake, Hardware Accelerated Visibility Preprocessing using Adaptive Sampling (http:/ / citeseerx. ist. psu. edu/<br />
viewdoc/ summary?doi=10. 1. 1. 64. 3231), Rendering Techniques 2004: Proceedings of the 15th Euro<strong>graphics</strong> Symposium on Rendering,<br />
207- 216, Norrköping, Sweden, June 2004.<br />
[5] Peter Wonka, Michael Wimmer, Kaichi Zhou, Stefan Maierhofer, Gerd Hesina, Alexander Reshetov. Guided Visibility Sampling (http:/ /<br />
citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 91. 5278), ACM Transactions on Graphics. volume 25. number 3. pages 494 - 502.<br />
2006. Proceedings of SIGGRAPH 2006.<br />
[6] Craig Gotsman, Oded Sudarsky, and Jeffrey A. Fayman. Optimized occlusion culling using five-dimensional subdivision (http:/ / www. cs.<br />
technion. ac. il/ ~gotsman/ AmendedPubl/ OptimizedOcclusion/ optimizedOcclusion. pdf), Computers & Graphics, 23(5):645–654, October<br />
1999.<br />
[7] Seth Teller, Visibility Computations in Densely Occluded Polyhedral Environments (http:/ / www. eecs. berkeley. edu/ Pubs/ TechRpts/ 1992/<br />
CSD-92-708. pdf) (Ph.D. dissertation, Berkeley, 1992)<br />
[8] Jiri Bittner. Hierarchical Techniques for Visibility Computations (http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 2. 9886),<br />
PhD Dissertation. Department of Computer Science and Engineering. Czech Technical University in Prague. Submitted October 2002,<br />
defended March 2003.<br />
[9] Denis Haumont, Otso Mäkinen and Shaun Nirenstein, A low Dimensional Framework for Exact Polygon-to-Polygon Occlusion Queries<br />
(http:/ / citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 66. 6371), Rendering Techniques 2005: Proceedings of the 16th Euro<strong>graphics</strong><br />
Symposium on Rendering, 211-222, Konstanz, Germany, June 2005<br />
[10] Jiri Bittner, Peter Wonka, Michael Wimmer. Fast Exact From-Region Visibility in Urban Scenes (http:/ / citeseerx. ist. psu. edu/ viewdoc/<br />
summary?doi=10. 1. 1. 71. 3271), In Proceedings of Euro<strong>graphics</strong> Symposium on Rendering 2005, pages 223-230.<br />
[11] D. Haumont, O. Debeir and F. Sillion, Graphics Forum, Volumetric Cell-and-Portal Generation (http:/ / citeseerx. ist. psu. edu/ viewdoc/<br />
summary?doi=10. 1. 1. 163. 6834), Volume 22, Number 3, pages 303-312, September 2003<br />
[12] Oliver Mattausch, Jiri Bittner, Michael Wimmer, Adaptive Visibility-Driven View Cell Construction (http:/ / citeseerx. ist. psu. edu/<br />
viewdoc/ summary?doi=10. 1. 1. 67. 6705), In Proceedings of Euro<strong>graphics</strong> Symposium on Rendering 2006.<br />
[13] Michiel van de Panne and A. James Stewart, Effective Compression Techniques for Precomputed Visibility (http:/ / citeseerx. ist. psu. edu/<br />
viewdoc/ summary?doi=10. 1. 1. 116. 8940), Euro<strong>graphics</strong> Workshop on Rendering, 1999, pg. 305-316, June.
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