一张图，开启四维时空：4DNeX让动态世界 「活」起来

Core Viewpoint - The article introduces 4DNeX, a groundbreaking framework developed by Nanyang Technological University S-Lab and Shanghai Artificial Intelligence Laboratory, which can generate 4D dynamic scenes from a single input image, marking a significant advancement in the field of AI and world modeling [2][3]. Group 1: Research Background - The concept of world models is gaining traction in AI research, with Google DeepMind's Genie 3 capable of generating interactive videos from high-quality game data, but lacking validation in real-world scenarios [5]. - A pivotal point in the development of world models is the ability to accurately depict dynamic 3D environments that adhere to physical laws, enabling realistic content generation and supporting "counterfactual" reasoning [5][6]. Group 2: 4DNeX-10M Dataset - The 4DNeX-10M dataset consists of nearly 10 million frames of 4D annotated video, covering diverse themes such as indoor and outdoor environments, natural landscapes, and human motion, with a focus on "human-centered" 4D data [10]. - The dataset is constructed using a fully automated data-labeling pipeline, which includes data sourcing from public video libraries and quality control measures to ensure high fidelity [12][14]. Group 3: 4DNeX Method Architecture - 4DNeX proposes a 6D unified representation that captures both appearance (RGB) and geometry (XYZ), allowing for the simultaneous generation of multi-modal content without explicit camera control [16]. - The framework employs a key strategy called "width fusion," which minimizes cross-modal distance by directly concatenating RGB and XYZ data, outperforming other fusion methods [18][20]. Group 4: Experimental Results - Experimental results demonstrate that 4DNeX achieves significant breakthroughs in both efficiency and quality, with a dynamic range of 100% and temporal consistency of 96.8%, surpassing existing methods like Free4D [23]. - User studies indicate that 85% of participants preferred the generated effects of 4DNeX, particularly noting its advantages in motion range and realism [23][25]. - Ablation studies confirmed the critical role of the width fusion strategy in optimizing multi-modal integration, eliminating noise and alignment issues present in other approaches [28].