Self-supervised Neural Articulated Shape and Appearance Models
(CVPR 2022)

Fangyin Wei1, Rohan Chabra2, Lingni Ma2, Christoph Lassner2, Michael Zollhöfer2,
Szymon Rusinkiewicz1, Chris Sweeney2, Richard Newcombe2, Mira Slavcheva2

1Princeton University       2Reality Labs Research

Animating Shapes from Real-world Static Images


Our self-supervised method learns the shape and appearance of articulated object classes. After training from multi-view synthetic images of different states of object instances, our model can reconstruct and animate objects from static real-world images

Abstract


Learning geometry, motion, and appearance priors of object classes is important for the solution of a large variety of computer vision problems. While the majority of approaches has focused on static objects, dynamic objects, especially with controllable articulation, are less explored. We propose a novel approach for learning a representation of the geometry, appearance, and motion of a class of articulated objects given only a set of color images as input. In a self-supervised manner, our novel representation learns shape, appearance, and articulation codes that enable independent control of these semantic dimensions. Our model is trained end-to-end without requiring any articulation annotations. Experiments show that our approach performs well for different joint types, such as revolute and prismatic joints, as well as different combinations of these joints. Compared to state of the art that uses direct 3D supervision and does not output appearance, we recover more faithful geometry and appearance from 2D observations only. In addition, our representation enables a large variety of applications, such as few-shot reconstruction, the generation of novel articulations, and novel view-synthesis.

Interactively Animating Shapes from Real-world RGB Images


Use the slider on the right to interactly animate the shapes.

Interpolate start reference image.

Input Static RGB Images

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Output Animation

Interpolate start reference image.

Input Static RGB Images

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Output Animation

Interactively Animating Shapes from SAPIEN Dataset Images


Use the slider on the right to interactly animate the shapes. All testing examples below are unseen during training.

Single Joint

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Double Joints

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Articulation Interpolation and Extrapolation


While A-SDF loses more details and the shape of non-motion parts may also change in A-SDF, our method predicts static non-motion parts and more accurate geometry during interpolation and extrapolation.

Interpolation

Extrapolation

Paper


Video


Bibtex



@inproceedings{wei2022nasam, title = {Self-supervised Neural Articulated Shape and Appearance Models}, author = {Fangyin Wei and Rohan Chabra and Lingni Ma and Christoph Lassner and Michael Zollhoefer and Szymon Rusinkiewicz and Chris Sweeney and Richard Newcombe and Mira Slavcheva}, booktitle = {Proceedings IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)}, year={2022} }