Hongzhi Wu 1,2, Li-Yi Wei 1, Xi Wang 1, and Baining Guo 1 Microsoft Research Asia 1 Fudan University...
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Hongzhi Wu 1,2 , Li-Yi Wei 1 , Xi Wang 1 , and Baining Guo 1 Microsoft Research Asia 1 Fudan University 2 Silhouette Texture
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Transcript of Hongzhi Wu 1,2, Li-Yi Wei 1, Xi Wang 1, and Baining Guo 1 Microsoft Research Asia 1 Fudan University...
Hongzhi Wu1,2, Li-Yi Wei1, Xi Wang1, and Baining Guo1
Microsoft Research Asia1 Fudan University2
Silhouette Texture
Problem
Silhouettes are importantVisual cues for human perception system
Render detailed silhouettes is expensivelow-polygon count objects causing jagged
silhouettes
Grand Theft Auto World of Warcraft
Our Solution
Render high quality silhouette with low polygon countIn the spirit of Silhouette Clipping [Sanders et al
00]Load balance for pixel for vertex stages
GPU today was optimized for ~ 10 pixels per vertex
(not true for dense meshes)
Outer hull + Normal map
Original Mesh (308 fps)
Our method (725 fps)
Previous Work
Silhouette Clipping [Sanders et al 00]Exterior silhouettes onlyExplicit storage of all original edgesNot GPU friendly
VDM/GDM [Wang et al 03,04] and Relief Mapping [Policarpo et al 05]Mainly for interior texture detailsDifficulty in handling silhouettes
Interactive Horizon Mapping [Sloan et al 00, Heidrich et al 00]Similar data structure, but for self-shadowing
Overview
Outer hull
Normal Map
Silhouette Texture
Final Result
Original Mesh
Simplify
Preprocess Render+
Correspondence: Outer hull and Original mesh
Original Mesh
Hull
p
Dp
q
Visibility Function
Our basic data structure for rendering silhouette
Original Mesh
p Dp
2D 3D
Algorithm Illustration
A Hull
A
B
Original Mesh
hit
miss
Quality Comparison
Normal map
Our approach
Difference
Incorrect Interior Silhouettes (Naïve Visibility Function)
A
Original Mesh
Hull
p1
q1
p2
q2 correctincorrect
Correct Interior Silhouettes (Modified Visibility Function)
A
Original Mesh
Hull
p1
q1q2
p2 q3correct
incorrect
Sampling Visibility Function
Store sampled spoke length into an 1D array
limitations8
124 3
6
5
7
1 2 3 4 5 6 7 8
Silhouette Texture Encoding/Decoding
angle
heig
ht
width
Silhouette Texture
SVD CompressionUncompressed
25% Compression Rate
12.5% Compression Rate
6.3% Compression Rate
Results
Outer hull + Normal map
Original Mesh (411 fps)
Our method (638 fps)
Bunny
Results
Outer hull + Normal map
Original Mesh (1.5 fps) Our method (273 fps)
Lucy
Performance
0
500
1, 000
1, 500
2, 000
2, 500
0 100, 000 200, 000 300, 000 400, 000 500, 000 600, 000
# pi xel s drawn
FPS
Our method Ori gi nal Mesh
0
200
400
600
800
1, 000
1, 200
1, 400
0 200, 000 400, 000 600, 000 800, 000 1, 000, 000
# pi xel s drawn
FPS
Our method Ori gi nal Mesh
Bunny
Lucy
Automatic geometry LOD control
Interpolation Quality
Entire mesh
Silhouette texture
(green grid)
Rendering Result
Smooth interpolation out of coarse silhouette texture grid
Outer Hull Resolution
22 vertices
102 vertices
500 vertices
Outer hull + Norm
al map
Our metho
d
Silhouette Texture Resolution
Spatial
5122
1282
322
Angular 64 16 4
Silhouette Visualization
802 fps 753 fps 787 fps
Future Work
Dynamic objectsStart with articulated figures
MIPMAP issueAutomatic geometry LOD control via texture
hardwareMIPMAP, anisotropy, etc
Thank you!
