Efficiently Reconstructing Dynamic Scenes One D4RT at a Time
Authors: name: Chuhan Zhang, name: Guillaume Le Moing, name: Skanda Koppula, name: Ignacio Rocco, name: Liliane Momeni, name: Junyu Xie, name: Shuyang Sun, name: Rahul Sukthankar, name: Joëlle K Barral, name: Raia Hadsell, name: Zoubin Ghahramani, name: Andrew Zisserman, name: Junlin Zhang, name: Mehdi SM Sajjadi
Organization: Google

Understanding and reconstructing the complex geometry and motion of dynamic scenes from video remains a formidable challenge in computer vision. This paper introduces D4RT, a simple yet powerful feedforward model designed to efficiently solve this task. D4RT utilizes a unified transformer architecture to jointly infer depth, spatio-temporal correspondence, and full camera parameters from a single video. Its core innovation is a novel querying mechanism that sidesteps the heavy computation of dense, per-frame decoding and the complexity of managing multiple, task-specific decoders. Our decoding interface allows the model to independently and flexibly probe the 3D position of any point in space and time. The result is a lightweight and highly scalable method that enables remarkably efficient training and inference. We demonstrate that our approach sets a new state of the art, outperforming previous methods across a wide spectrum of 4D reconstruction tasks. We refer to the project webpage for animated results: https://d4rt-paper.github.io/.