Abstract
The recent advance of neural fields, such as neural radiance fields, has significantly pushed the boundary of scene representation learning. Aiming to boost the computational efficiency and rendering quality of 3D scenes, a popular line of research maps the 3D coordinate system to another measuring system, e.g., 2D manifolds and hash tables, for modeling neural fields. The conversion of coordinate systems can be typically dubbed as gauge transformation, which is usually a pre-defined mapping function, e.g., orthogonal projection or spatial hash function. This begs a question: can we directly learn a desired gauge transformation along with the neural field in an end-to-end manner? In this work, we extend this problem to a general paradigm with a taxonomy of discrete and continuous cases, and develop an end-to-end learning framework to jointly optimize the gauge transformation and neural fields. To counter the problem that the learning of gauge transformations can collapse easily, we derive a general regularization mechanism from the principle of information conversation during the gauge transformation. On the strength of the derived unified neural gauge field framework, we naturally discover a new type of gauge transformation which achieves a trade-off between learning collapse and computational cost.
Video
Reflection Direction Parameterization
Integrated Directional Encoding

Additional Synthetic Results
Results on Captured Scenes
Our method also produces accurate renderings and surface normals from captured photographs:Scene Editing
We can increase and decrease material roughness:
Citation
Acknowledgements
We would like to thank Lior Yariv and Kai Zhang for helping us evaluate their methods, and Ricardo Martin-Brualla for helpful comments on our text. DV is supported by the National Science Foundation under Cooperative Agreement PHY-2019786 (an NSF AI Institute, http://iaifi.org)
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