🤖 AI Summary
Existing 3D reconstruction methods struggle to balance generalization and practicality due to either inefficient per-scene optimization or reliance on category-specific training. This work proposes a feed-forward, output-representation-agnostic framework for 3D reconstruction, systematically addressing five core challenges: feature enhancement, geometry awareness, model efficiency, data augmentation, and temporal modeling. By unifying the analysis of image backbones, multi-view fusion mechanisms, and geometric priors—and integrating major datasets and evaluation benchmarks—it establishes a standardized benchmarking protocol. The study transcends differences in geometric representations, formulates a problem-driven, generalizable modeling paradigm, and outlines promising future directions in scalability, evaluation metrics, and world modeling.
📝 Abstract
Reconstructing 3D representations from 2D inputs is a fundamental task in computer vision and graphics, serving as a cornerstone for understanding and interacting with the physical world. While traditional methods achieve high fidelity, they are limited by slow per-scene optimization or category-specific training, which hinders their practical deployment and scalability. Hence, generalizable feed-forward 3D reconstruction has witnessed rapid development in recent years. By learning a model that maps images directly to 3D representations in a single forward pass, these methods enable efficient reconstruction and robust cross-scene generalization. Our survey is motivated by a critical observation: despite the diverse geometric output representations, ranging from implicit fields to explicit primitives, existing feed-forward approaches share similar high-level architectural patterns, such as image feature extraction backbones, multi-view information fusion mechanisms, and geometry-aware design principles. Consequently, we abstract away from these representation differences and instead focus on model design, proposing a novel taxonomy centered on model design strategies that are agnostic to the output format. Our proposed taxonomy organizes the research directions into five key problems that drive recent research development: feature enhancement, geometry awareness, model efficiency, augmentation strategies and temporal-aware models. To support this taxonomy with empirical grounding and standardized evaluation, we further comprehensively review related benchmarks and datasets, and extensively discuss and categorize real-world applications based on feed-forward 3D models. Finally, we outline future directions to address open challenges such as scalability, evaluation standards, and world modeling.