1. Quirin Meyer 1, Christian Eisenacher 1, Marc Stamminger 1, Carsten Dachsbacher 2 1 Erlangen-Nuremberg University, Department Informatik, Computer Graphics 2 Stuttgart University, VIS/VISUS

6.  

8.   oracle?

15.  Link & hierarchy creation ◦ Hierarchy of patches...............

16.  Link & hierarchy creation ◦ Hierarchy of patches ◦ Hierarchy of links...............

17.  Link & hierarchy creation ◦ Hierarchy of patches ◦ Hierarchy of links  Transport light over links ◦ Keep hierarchy consistent ◦ Convolute with BRDF Create Links and Patch Hierarchy Simulate Light Transport Display  Display

18.  Link & hierarchy creation ◦ Hierarchy of patches ◦ Hierarchy of links Create Links and Patch Hierarchy Simulate Light Transport Display Simulate Light Transport Display  Transport light over links ◦ Keep hierarchy consistent ◦ Convolute with BRDF  Display GPU APPROVED

19.  Link creation still not on the GPU!  Problem on the GPU: ray casts for explicit visibility computation  New radiosity-like methods: ◦ Implicit Visibility [Dong07] ◦ Antiradiance [Dachsbacher07] ◦ Directional discretization Create Links and Patch Hierarchy Simulate Light Transport Display

28.  Goal: interactive global illumination  Visibility without ray casts allows patch hierarchy & link creation on the GPU  How to parallelize? ◦ Parallelism over the links ◦ Parallel job queue of links ◦ Mark used patches on the way to create a compact hierarchy of patches

29. ... oracle scan refine

30. oracle

32. 4 4

33. 4 4

34. 4 4

35. 4 4 4 4

36. 4 4 4 4

37. 4 4 4 4

38. 4 4 4 4 1 1

39. 4 4 4 4 1 1

40. 4 4 4 4 1 1

41. 4 4 4 4 1 1 1 1

42. 4 4 4 4 1 1 1 1

43. 4 4 4 4 1 1 1 1

44. 4 4 4 4 1 1 1 1 4 4

45. 4 4 4 4 1 1 1 1 4 4

46. 4 4 4 4 1 1 1 1 4 4

47. 4 4 4 4 1 1 1 1 4 4 scan

48. 0 4 4 4 4 1 1 1 1 4 4

49. 0 0 4 4 4 4 4 1 1 1 1 4 4

50. 0 0 4 4 4 4 4 4 1 1 1 1 4 4 8

51. 0 0 4 4 4 4 4 4 1 1 1 1 4 4 8 8 9

52. 0 0 4 4 4 4 4 4 1 1 1 1 4 4 8 8 9 9 10

53. 0 0 4 4 4 4 4 4 1 1 1 1 4 4 scan 8 8 9 9 10 14

54. 4 4 4 4 1 1 1 1 4 4 scan 0 0 4 4 8 8 9 9 10 14

55. 4 4 4 4 1 1 1 1 4 4 scan 0 0 4 4 8 8 9 9 10 14

56. 0 0 4 4 8 8 9 9 10 14

57. refine 0 0 4 4 8 8 9 9 10 14

58. 0 0 4 4 8 8 9 9 10 14 refine

59. 0 0 4 4 8 8 9 9 10 14 refine

60. 0 0 4 4 8 8 9 9 10 14 refine

61. 0 0 4 4 8 8 9 9 10 14 refine

62. 0 0 4 4 8 8 9 9 10 14 refine

63. ... oracle scan refine Until all links are ready!

64. 64 bins ≡ 1 KiB 128 bins ≡ 2 KiB 256 bins ≡ 4 KiB

65. 4253 Nodes ~ 4 MB17745 Nodes ~ 17 MB

66. refine 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1

67. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1

68. 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0

69. 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 1 1

70. 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1

71. 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1

72. 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0

73. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5 5 5 5 5 5 5 5 5 5 1 1 5 5 5 5 5 5 2 2 7 7 6 6 8 8 5 5 3 3 9 9 9 9 9 9 9 9 4 4 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 scan

74. 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5 5 5 5 5 5 5 5 5 5 1 1 5 5 5 5 5 5 2 2 7 7 6 6 8 8 5 5 3 3 9 9 9 9 9 9 9 9 4 4 0 0

75. 1 1 2 2 3 3 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 7 7 6 6 8 8 5 5 9 9 9 9 9 9 9 9 4 4 0 0

76. 5 5 5 5 5 5 5 5 1 1 5 5 5 5 5 5 5 5 2 2 7 7 6 6 8 8 5 5 3 3 9 9 9 9 9 9 9 9 4 4 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1

77.  Bin search  Link recoding  Form Factors  Implicit Visibility: Only keep shortest link  Topology

78. Link Creation: 24.2 ms Links:1.1 M Patches:21 k Bins:256 3 Iter. AR:53.1 ms Total FPS:11 fps

79. Antiradiance Implicit Visibility 0.20.40.60.81.0.1.20.0 256 bins

80. 1 Iteration 2 Iteration 3 Iteration Link Creation 0.20.40.60.81.0.1.20.0 256 bins 12 fps 25 fps 50 fps 81 fps

81. 1 Iteration 2 Iteration 3 Iteration Link Creation 0.20.40.60.81.0.1.20.0 256 bins 15-85 fps

82. Oracle Scan Refine Mark Recode Topology Min. Link IV only 1.1 M Links and 21 k Patches 2.9 ms 8.0 ms 1.2 ms 5.5 ms 6.3 ms 5.6 ms 0.3 ms

83.  Link creation time ~ solution time  Surprisingly simple kernels  Performance ◦ Transferring 1 M links from CPU to GPU13.2 ms ◦ Creating 1 M links on the GPU24.2 ms  Global atomics not evil

84.  No clustering („surfel-hierarchy“ ) [Dong07]  Maximum depth of perfect patch tree  Memory consumption: 82.9 MB for 21 k patches

85.  Link creation for hierarchical radiosity on GPU ◦ Link hierarchy ◦ Compact patch hierarchy  Two methods ◦ Antiradiance: 50 M links / second ◦ Implicit Visibility: 15 M links / second ◦ Dynamic, interactive scenes

86.  Link Creation ◦ BF-refinement ◦ Clustering  Antiradiance/Implicit Visibility ◦ Reduce storage costs per node ◦ Light transport