Deep Implicit Surface Point Prediction Networks

Carnegie Mellon University Pittsburgh, PA, USA Indian Institute of Science, Bengaluru, India

Verisk Analytics, Jersey City, NJ, USA

Abstract

Deep neural representations of 3D shapes as implicit functions have been shown to produce high fidelity models surpassing the resolution-memory trade-off faced by the explicit representations using meshes and point clouds. However, most such approaches focus on representing closed shapes. Unsigned distance function (UDF) based approaches have been proposed recently as a promising alternative to represent both open and closed shapes. However, since the gradients of UDFs vanish on the surface, it is challenging to estimate local (differential) geometric properties like the normals and tangent planes which are needed for many downstream applications in vision and graphics. There are additional challenges in computing these properties efficiently with a low-memory footprint. This paper presents a novel approach that models such surfaces using a new class of implicit representations called the closest surface-point (CSP) representation. We show that CSP allows us to represent complex surfaces of any topology (open or closed) with high fidelity. It also allows for accurate and efficient computation of local geometric properties. We further demonstrate that it leads to efficient implementation of downstream algorithms like sphere-tracing for rendering the 3D surface as well as to create explicit mesh-based representations. Extensive experimental evaluation on the ShapeNet dataset validate the above contributions with results surpassing the state-of- the-art.

Overview

TL; DR: CSPNet follows a simple objective to represent a shape: given a query point p, it learns the closest point to it on the surface.

Results

Surface Reconstruction

High-fidelity surface reconstruction from CSPNet. Note the reconstruction of thin legs of the table and hollow frustum of the lamp from CSP.

Normal Estimation

CSP objective can define accurate on-surface normals, which can be validated in the following examples:

Citation

If you find our work helpful in your research, please cite our work:

@InProceedings{Venkatesh_2021_ICCV,

author = {Venkatesh, Rahul and Karmali, Tejan and Sharma, Sarthak and Ghosh, Aurobrata and Babu, R. Venkatesh and Jeni, Laszlo A. and Singh, Maneesh},

title = {Deep Implicit Surface Point Prediction Networks},

booktitle = {Proceedings of the IEEE/CVF International Conference on Computer Vision (ICCV)},

month = {October},

year = {2021},

pages = {12653-12662}

}


Licence

This project is licenced under an [MIT License].