Original title: Unfold The World: Factorize 4D Properties in Reinforcing Spatial Reasoning
Yijun Yang, Shenghe Zheng, Wenbo Li, Jianhui Liu +7 · September 2026
Vision-Language Models combine text and pictures to answer questions. However, they struggle to understand the physical world because they learn from flat, two-dimensional images instead of real three-dimensional space over time. Researchers created FactoSR to solve this problem. FactoSR uses reinforcement learning, a method where an artificial intelligence learns by getting rewards for correct steps. It breaks the big challenge of world reasoning into three smaller, clear goals: tracking positions across a flat plane, keeping depth consistent, and preserving time going forward and backward. By training the model to check these three physical rules step by step, the system better understands scenes. When tested, this method improved performance by 5.9% on VSI-Bench and 4.5% on All-Angles-Bench.
Imagine packing a suitcase for a trip where you need to fit clothes, shoes, and toiletries in a small bag. If you just stuff everything in at once, things get crushed or you run out of space. In this paper, the system breaks the task into organizing where items are on a plane, how deep they are, and when you need to access them, making it much easier to fit everything perfectly.
This matters for AI systems that need to understand physical spaces, such as self-driving cars or augmented reality. By fixing the dimensional mismatch, these models can reason more reliably about 3D and 4D environments from 2D images.
The abstract does not establish generalizability beyond the multi-view and video benchmarks used in evaluations, and it does not discuss other potential challenges or applications.
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Unfold The World: Factorize 4D Properties in Reinforcing Spatial Reasoning — Yijun Yang, Shenghe Zheng, Wenbo Li et al.
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.