VSP: Assessing the dual challenges of perception and reasoning in spatial planning tasks for VLMs
Qiucheng Wu, Handong Zhao, Michael Saxon, Trung Bui, William Yang Wang, Yang Zhang, Shiyu Chang
TL;DR
<3-5 sentence high-level summary> The paper introduces Visual Spatial Planning (VSP), a benchmark designed to evaluate how vision-language models perceive spatial layouts and formulate action plans in visual scenes. It comprises two scenarios, Maze Navigation and Blocks World, each with four sub-tasks that isolate perception and reasoning, totaling about 4.4k questions with progressive difficulty. Across a range of private and open-source baselines, the study reveals substantial gaps in both perception and reasoning, with perception identified as a primary bottleneck; textual input can mitigate some perception issues, highlighting where models struggle. The authors further show that targeted fine-tuning on open-source models yields improvements and discuss directions for stronger spatial understanding and planning in VLMs, with the benchmark and evaluation scripts publicly released to foster progress.
Abstract
Vision language models (VLMs) are an exciting emerging class of language models (LMs) that have merged classic LM capabilities with those of image processing systems. However, the ways that these capabilities combine are not always intuitive and warrant direct investigation. One understudied capability in VLMs is visual spatial planning -- the ability to comprehend the spatial arrangements of objects and devise action plans to achieve desired outcomes in visual scenes. In our study, we introduce VSP, a benchmark that 1) evaluates the spatial planning capability in these models in general, and 2) breaks down the visual planning task into finer-grained sub-tasks, including perception and reasoning, and measure the LMs capabilities in these sub-tasks. Our evaluation shows that both open-source and private VLMs fail to generate effective plans for even simple spatial planning tasks. Evaluations on the fine-grained analytical tasks further reveal fundamental deficiencies in the models' visual perception and bottlenecks in reasoning abilities, explaining their worse performance in the general spatial planning tasks. Our work illuminates future directions for improving VLMs' abilities in spatial planning. Our benchmark is publicly available at https://github.com/UCSB-NLP-Chang/Visual-Spatial-Planning.
