a fast deferred shading algorithm for approximate indirect illumination
DESCRIPTION
Siggraph 2010 – "Split Second Screen Space". A Fast Deferred Shading Algorithm for Approximate Indirect Illumination. Olivier Hoël Cyril Soler. Frank Rochet. Motivations. Direct lighting only. With indirect lighting. Greatly enhance realism and immersion But expensive to compute. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/1.jpg)
![Page 2: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/2.jpg)
A Fast Deferred Shading Algorithm for Approximate
Indirect Illumination
Siggraph 2010 – "Split Second Screen Space"
Olivier HoëlCyril Soler
Frank Rochet
![Page 3: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/3.jpg)
3
Motivations• Greatly enhance realism and immersion• But expensive to compute
Direct lighting only With indirect lighting
![Page 4: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/4.jpg)
Video games constraints• 30fps => at most ~10ms for indirect lighting• Dynamic environment• Independent of geometry / lighting complexity• Any kind of illumination source• Artifact free result
4
![Page 5: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/5.jpg)
Video games constraints30fps => at most ~10ms for indirect lightingDynamic environmentIndependent of geometry / lighting complexityAny kind of illumination sourceArtifact free resultDeferred shading pipeline
5
![Page 6: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/6.jpg)
6
Deferred shading• Two steps– Render Geometry Buffer (G-Buffer)– Compute lighting as post-process
• Pros / Cons– Hidden objects => approximate
» Included solution to remove artifact – Screen Space => FAST
![Page 7: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/7.jpg)
Outline
I. Related WorkII. Screen Space samplingIII. PipelineIV. Results
7
![Page 8: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/8.jpg)
8
Related Work
Imperfect Shadow Map [RGK*08] Multi-resolution splatting of Indirect Illumination [NW09]
Hierarchical Image-space Radiosity [NSW09]Cascaded Light Propagation Volumes [KD10]
![Page 9: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/9.jpg)
9
Comparison[RGK*08] [NW09] [NSW09] [KD10] Ours
No pre-computation Constant cost w.r.t lighting
complexity
Any kind of light source
Multiple bounces
Visibility
![Page 10: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/10.jpg)
Outline
I. Related Work
II. Screen Space samplingIII. PipelineIV. Results
10
![Page 11: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/11.jpg)
11
Screen Space Indirect Illumination
• Monte-Carlo integration on G-Buffer• Hierarchical computation using mipmaps– Arbitrary distance– Save performances
![Page 12: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/12.jpg)
12
G-Buffer’
G-Buffer
Input structure
+Direct Lighting
Mipmaps Set Pixel Shader
Dept
hN
orm
alAl
bedo
![Page 13: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/13.jpg)
13
Sampling scheme (1/3)• Random screen space samples on disk• Efficient use of texture cache• Constant radius over all set of mipmap
Mipmap set at level l
Mipmap set at level l+1dd/2
![Page 14: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/14.jpg)
14
Sampling scheme (2/3)
![Page 15: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/15.jpg)
15
Importance sampling (3/3)
Level 0
Level k>0
Level 0
Level k>0
![Page 16: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/16.jpg)
16
Monte-Carlo reformulation
Using point to point form factor Using point to disc form factor
![Page 17: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/17.jpg)
17
Visibility• Fast scene voxelization from [ED08a]
• Trace rays to samples to resolve visibilitySingle-Pass GPU Solid Voxelization for Real-Time Applications [ED08a]
![Page 18: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/18.jpg)
18
G-Buffer’’
Visibility – New input
+
Mipmaps Set Pixel Shader
![Page 19: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/19.jpg)
19
Visibility - Results
Without visibility With visibility
![Page 20: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/20.jpg)
Outline
I. Related WorkII. Screen Space sampling
III. PipelineIV. Results
20
![Page 21: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/21.jpg)
21
Mipmapping (1/3)
• Interpolate normals / depth ?• “Nearest”: inconsistent over time
Source of variance => need a specific scheme• /!\ Voxel grid is binary
=> Bitwise operator
![Page 22: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/22.jpg)
22
Mipmapping (2/3)
• Voting scheme to favor large objectsComparing geometric similarity with neighbor pixelsÞ Discard small areasÞ Consistent over frames
![Page 23: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/23.jpg)
23
Mipmapping (3/3)
Full resolution normal buffer
4th mipmap using “Nearest” filtering 4th mipmap using “Largest” filtering
![Page 24: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/24.jpg)
24
Hierarchical upsampling (1/2)
• Different resolution to combine– No overlapping => ADD
• Coarse and noisy– Use cross bilateral filter hierarchically
+? +? +?+ + +
![Page 25: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/25.jpg)
25
Hierarchical upsampling (2/2)
lv3f
+
lv2
f
+
lv1
lv0
f
+
f(lv3)
f( lv2 + f(lv3) )
f
f( lv1 + f(lv2 + f(lv3)) )
Final indirect lighting
f = cross bilateral upsampling
![Page 26: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/26.jpg)
26
Temporal coherence
Reverse Reprojection Caching [Nehab et al 07]
Hit?
Average
Compute ReprojectUpdateno
yes
![Page 27: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/27.jpg)
27Reprojection & Compositing
Pipeline Summary
Indirect Lighting
G-Buffer’’
+
Mipmaps Set Filter & Blend
f
+
+
f
f
Previous frame
Albedo~ x
Direct Lighting
+
Input to bounce n+1
Direct Lighting / Bounce n-1
![Page 28: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/28.jpg)
Outline
I. Related WorkII. Screen Space samplingIII. Pipeline
IV.Results
28
![Page 29: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/29.jpg)
29
![Page 30: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/30.jpg)
30
![Page 31: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/31.jpg)
31
Real Time Video
GeForce GTX 260 @ 1280x720 – Using 256 samples
![Page 32: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/32.jpg)
32
Performances• Performance / Quality trade off – Quality: starting level & Number of samples– Range: sampling radius vs. number of levels
![Page 33: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/33.jpg)
33
Real time !Starting res. : 1/4
Levels: 4Samples: 64
Starting res. : 1/4Levels: 4
Samples: 256
Starting res. : 1/2 Levels: 4
Samples: 64
Starting res. : 1/2Levels: 5
Samples: 64
Visibility Without With Without With Without With Without With
Voxelization (ms) 4.5 4.5 4.5 4.5
Indirect lighting (ms) 2.3 50.2 8.9 188 7.8 125 7.85 129
Upsampling & Compositing (ms) 2.3 2.3 2.3 2.3 2.7 2.7 2.7 2.7
Total (ms) 4.6 57 11.2 195 10.5 132 10.55 136
GeForce GTX 260 @ 1280x720
![Page 34: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/34.jpg)
34
Visibility Starting res. : 1/4
Levels: 4Samples: 64
Starting res. : 1/4Levels: 4
Samples: 256
Starting res. : 1/2 Levels: 4
Samples: 64
Starting res. : 1/2Levels: 5
Samples: 64
Visibility Without With Without With Without With Without With
Voxelization (ms) 4.5 4.5 4.5 4.5
Indirect lighting (ms) 2.3 50.2 8.9 188 7.8 125 7.85 129
Upsampling & Compositing (ms) 2.3 2.3 2.3 2.3 2.7 2.7 2.7 2.7
Total (ms) 4.6 57 11.2 195 10.5 132 10.55 136
GeForce GTX 260 @ 1280x720
![Page 35: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/35.jpg)
35
Trade offStarting res. : 1/4
Levels: 4Samples: 64
Starting res. : 1/4Levels: 4
Samples: 256
Starting res. : 1/2 Levels: 4
Samples: 64
Starting res. : 1/2Levels: 5
Samples: 64
Visibility Without With Without With Without With Without With
Voxelization (ms) 4.5 4.5 4.5 4.5
Indirect lighting (ms) 2.3 50.2 8.9 188 7.8 125 7.85 129
Upsampling & Compositing (ms) 2.3 2.3 2.3 2.3 2.7 2.7 2.7 2.7
Total (ms) 4.6 57 11.2 195 10.5 132 10.55 136
GeForce GTX 260 @ 1280x720
![Page 36: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/36.jpg)
36
Trade offStarting res. : 1/4
Levels: 4Samples: 64
Starting res. : 1/4Levels: 4
Samples: 256
Starting res. : 1/2 Levels: 4
Samples: 64
Starting res. : 1/2Levels: 5
Samples: 64
Visibility Without With Without With Without With Without With
Voxelization (ms) 4.5 4.5 4.5 4.5
Indirect lighting (ms) 2.3 50.2 8.9 188 7.8 125 7.85 129
Upsampling & Compositing (ms) 2.3 2.3 2.3 2.3 2.7 2.7 2.7 2.7
Total (ms) 4.6 57 11.2 195 10.5 132 10.55 136
GeForce GTX 260 @ 1280x720
![Page 37: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/37.jpg)
37
Discussion
• Memory cost– But works fine on PC
• Indirect Visibility– Computationally expensive– Not visually relevant - [Perceptual Influence of Approximate
Visibility in Indirect Illumination - Yu et al 2009]
![Page 38: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/38.jpg)
38
Conclusion• Cool results at constant cost• Real time !
• Use frequency information
![Page 39: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/39.jpg)
39
References• Technical report
http://artis.imag.fr/Membres/Cyril.Soler/SSIL/ssil.techreport.2010.pdf
• Contact:[email protected]@[email protected]
![Page 40: A Fast Deferred Shading Algorithm for Approximate Indirect Illumination](https://reader035.vdocuments.site/reader035/viewer/2022062814/56816728550346895ddbc4be/html5/thumbnails/40.jpg)
Thanks !• Technical report
http://artis.imag.fr/Membres/Cyril.Soler/SSIL/ssil.techreport.2010.pdf• Contact:
[email protected] / [email protected] / [email protected]
• AcknowledgmentsK. Subr & N. Holzschuch (INRIA) for nice reviewsEngineers and artists from Eden Games for useful advices