Revisiting Siamese-Based 3D Single Object Tracking With a Versatile Transformer.

3D Single Object Tracking (SOT) plays an important role in real-world visual applications such as autonomous driving and planning. How to realize effective 3D SOT is still a valuable challenge due to its carrier-sparse point clouds and its role-complex influencing factors. Inspired by the remote modeling of popular transformers, we further propose a Versatile Point Tracking Transformer (VPTT) method for 3D SOT, with object guidance from the template point cloud to the search area point cloud under the siamese-based tracking paradigm. Specifically, VPTT employs self- and cross- attention mechanisms and extends four matching operations, resulting in leveraging the contextual information of consecutive frames to improve the tracking results. By constructing a deep network VerFormer consisting of four successive transformer layers, which performs matching operations involving fusional transformation, separative discrimination, intersectional interaction, and unidirectional propagation from shallow to deep. Considering that the tracking task involves multiple processes, VPTT further learns how to forecast intermediate outputs including mask probability, trailing distance, and heading angle at each stage. Such a specialized design allows our VPTT to revisit the end-to-end training paradigm used for 3D tracking while developing a versatile transformer that is a perfect fit for the 3D SOT task. Experiments on three benchmarks, KITTI, nuScenes, and Waymo, show that VPTT achieves state-of-the-art tracking performance on siamese-based tracking running at $\sim$∼62 FPS.