BSP-Net: Generating Compact Meshes via Binary Space Partitioning - - PowerPoint PPT Presentation

bsp net generating compact meshes via binary space
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BSP-Net: Generating Compact Meshes via Binary Space Partitioning - - PowerPoint PPT Presentation

BSP-Net: Generating Compact Meshes via Binary Space Partitioning Zhiqin Chen Andrea Tagliasacchi Hao (Richard) Zhang Simon Fraser University Google Research Simon Fraser University Presented by Zhiqin


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Presented by

陈之钦,西蒙弗雷泽大学

Zhiqin Chen, Ph.D. student, Simon Fraser University

BSP-Net: Generating Compact Meshes via Binary Space Partitioning

Zhiqin Chen Simon Fraser University Andrea Tagliasacchi Google Research Hao (Richard) Zhang Simon Fraser University

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3D shape representations

2 Mesh ShapeNet

Chang et al, arXiv

PolyGen

Nash et al, arXiv

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3D shape representations

3 Voxel 3D-R2N2

Choy et al, ECCV 2016

3DGAN

Wu et al, NIPS 2016

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3D shape representations

4 Point cloud

Learning Representations and Generative Models for 3D Point Clouds Achlioptas et al, ICML 2018

z (128d) 512 1024 6144 = 2048x3 FC FC FC

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3D shape representations

5 3DN

Wang et al, CVPR 2019

AtlasNet

Groueix et al, CVPR 2018

Warping template meshes Pixel2mesh

Wang et al, ECCV 2018

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3D shape representations

6 implicit field

IM-NET

Chen & Zhang, CVPR 2019

OccNet

Mescheder et al, CVPR 2019

DeepSDF

Park et al, CVPR 2019

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Compactness / low-poly / sharp details

Chen & Zhang, CVPR 2019

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Compactness / low-poly / sharp details

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Represent shapes as Binary Space Partitioning trees

*CSG operations – Constructive Solid Geometry operations

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max-pooling min-pooling

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Network architecture

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max-pooling min-pooling Dnxp Tpxc

D[: , 0]

Cnxc S*nx1

[: , 1] [: , 2] [: , 3] [: , 4] [: , 5] [: , 6] [: , 7] [: , 8] C[: , 0]

[: , 2] [: , 1]

  • 1

+1

shape surface 0

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Network architecture

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max-pooling min-pooling

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Network architecture

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max-pooling min-pooling

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Replacing max/min with weighted sum

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Replacing max/min with weighted sum

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Dnxp Tpxc

D[: , 0]

Cnxc=relu(Dnxp)T S+nx1

[: , 1] [: , 2] [: , 3] [: , 4] [: , 5] [: , 6] [: , 7] [: , 8]

relu(Dnxp) relu(x) relu(1-Cnxc)

+ + + +

relu(1-Cnxc) 1cx1 relu(1-x)

1 ≈0

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Replacing max/min with weighted sum

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Dnxp Tpxc

D[: , 0]

Cnxc=relu(Dnxp)T S+nx1

[: , 1] [: , 2] [: , 3] [: , 4] [: , 5] [: , 6] [: , 7] [: , 8]

relu(Dnxp) relu(x) [1-Cnxc][0,1] ≈relu(1-Cnxc)

+ + + +

[1-Cnxc][0,1] 1cx1 ≈relu(1-Cnxc) 1cx1

1 ≈0

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Replacing max/min with weighted sum

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Dnxp Tpxc

D[: , 0]

Cnxc=relu(Dnxp)T S+nx1

[: , 1] [: , 2] [: , 3] [: , 4] [: , 5] [: , 6] [: , 7] [: , 8]

relu(Dnxp) relu(x) [1-Cnxc][0,1] ≈relu(1-Cnxc)

+ + + +

[1-Cnxc][0,1] Wcx1 ≈relu(1-Cnxc) 1cx1

1 ≈0

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Replacing max/min with weighted sum

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Dnxp Tpxc

D[: , 0]

Cnxc=relu(Dnxp)T S+nx1

[: , 1] [: , 2] [: , 3] [: , 4] [: , 5] [: , 6] [: , 7] [: , 8]

relu(Dnxp) relu(x) [1-Cnxc][0,1] ≈relu(1-Cnxc)

+ + + +

[1-Cnxc][0,1] Wcx1 ≈relu(1-Cnxc) 1cx1

1 ≈0

[ [1 - relu(xPT) T ][0,1] W ][0,1]

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Replacing max/min with weighted sum

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Dnxp Tpxc

D[: , 0]

Cnxc=relu(Dnxp)T S+nx1

[: , 1] [: , 2] [: , 3] [: , 4] [: , 5] [: , 6] [: , 7] [: , 8]

relu(Dnxp) relu(x) [1-Cnxc][0,1] ≈relu(1-Cnxc)

+ + + +

[1-Cnxc][0,1] Wcx1 ≈relu(1-Cnxc) 1cx1

1 ≈0

[ [1 - relu(xPT) T ][0,1] W ][0,1]

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Continuous weights Continuous weights Planes Convexes Output shape

Visualizing training - Initialization

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Visualizing training - Continuous phase

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Binary weights Min-pooling

Visualizing training – Discrete phase

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Binary weights Min-pooling

Visualizing training – Discrete phase

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Visualizing training – Discrete phase

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Toy dataset – 12 examples

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Toy dataset - Reconstruction

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Volumetric Primitives

Tulsiani et al, CVPR 2017

SuperQuadrics

Paschalidou et al, CVPR 2019

BAE-NET

Chen et al, ICCV 2019

BSP-NET (ours) Reconstruction ground truth

3D Reconstruction – Part Decomposition

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Single View Reconstruction (RGB→3D)

ResNet BSP-Net ResNet BSP-Net ResNet BSP-Net ResNet BSP-Net ResNet BSP-Net

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AtlasNet (1 sphere)

Groueix et al, CVPR 2018

AtlasNet (25 patches)

Groueix et al, CVPR 2018

Input image

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Quantitative results

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Thank you. Q&A

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