FLAT: Flux-aware Imperceptible Adversarial Attacks on 3D Point Clouds

Adversarial attacks on point clouds play a vital role in assessing and enhancing the adversarial robustness of 3D deep learning models. While employing a variety of geometric constraints, existing adversarial attack solutions often display unsatisfactory imperceptibility due to inadequate consideration of uniformity changes. In this paper, we propose FLAT, a novel framework designed to generate imperceptible adversarial point clouds by addressing the issue from a flux perspective. Specifically, during adversarial attacks, we assess the extent of uniformity alterations by calculating the flux of the local perturbation vector field. Upon identifying a high flux, which signals potential disruption in uniformity, the directions of the perturbation vectors are adjusted to minimize these alterations, thereby improving imperceptibility. Extensive experiments validate the effectiveness of FLAT in generating imperceptible adversarial point clouds, and its superiority to the state-of-the-art methods. Codes and pretrained models will be made public upon paper acceptance.