LRR-Bench: Left, Right or Rotate? Vision-Language models Still Struggle With Spatial Understanding Tasks
Fei Kong
TL;DR
LRR-Bench presents a fully synthetic spatial reasoning benchmark for Vision-Language Models, focusing on absolute positioning and 3D spatial understanding, including rotation and movement in 2D/3D settings. The authors build a low-cost generation pipeline using diffusion models and Minecraft, with filtering via GroundingDINO and SAM, and evaluate 20+ LVLMs under direct and reasoning-augmented prompts. Results show humans outperform models by a wide margin, with VLMs achieving near-random performance on most 3D tasks and only modest gains on the simplest absolute-position tasks, highlighting persistent spatial understanding gaps. The work argues synthetic data is viable for rigorous spatial reasoning evaluation, and suggests that model scaling, 3D-finetuning, and reasoning prompts do not reliably close the gap, pointing to new directions in spatial cognition research.
Abstract
Real-world applications, such as autonomous driving and humanoid robot manipulation, require precise spatial perception. However, it remains underexplored how Vision-Language Models (VLMs) recognize spatial relationships and perceive spatial movement. In this work, we introduce a spatial evaluation pipeline and construct a corresponding benchmark. Specifically, we categorize spatial understanding into two main types: absolute spatial understanding, which involves querying the absolute spatial position (e.g., left, right) of an object within an image, and 3D spatial understanding, which includes movement and rotation. Notably, our dataset is entirely synthetic, enabling the generation of test samples at a low cost while also preventing dataset contamination. We conduct experiments on multiple state-of-the-art VLMs and observe that there is significant room for improvement in their spatial understanding abilities. Explicitly, in our experiments, humans achieve near-perfect performance on all tasks, whereas current VLMs attain human-level performance only on the two simplest tasks. For the remaining tasks, the performance of VLMs is distinctly lower than that of humans. In fact, the best-performing Vision-Language Models even achieve near-zero scores on multiple tasks. The dataset and code are available on https://github.com/kong13661/LRR-Bench.
