Neural Implicit Surface Evolution

TL;DR

This paper introduces a neural implicit surface model that evolves over time using the level set equation, enabling continuous geometric transformations and interpolations without supervision.

Contribution

It extends neural implicit surfaces to space-time, allowing modeling of dynamic surfaces and geometric evolutions with a novel training approach.

Findings

Successfully models surface evolution under various vector fields.

Achieves smooth and sharp surface transformations using curvature equations.

Faster convergence when initialized with previous conditions.

Abstract

This work investigates the use of smooth neural networks for modeling dynamic variations of implicit surfaces under the level set equation (LSE). For this, it extends the representation of neural implicit surfaces to the space-time $\mathbb{R}^3\times \mathbb{R}$, which opens up mechanisms for continuous geometric transformations. Examples include evolving an initial surface towards general vector fields, smoothing and sharpening using the mean curvature equation, and interpolations of initial conditions. The network training considers two constraints. A data term is responsible for fitting the initial condition to the corresponding time instant, usually $\mathbb{R}^3 \times \{0\}$. Then, a LSE term forces the network to approximate the underlying geometric evolution given by the LSE, without any supervision. The network can also be initialized based on previously trained initial conditions, resulting in faster convergence compared to the standard approach.