  Human-Scene Interaction (HSI) is a vital component of fields like embodied AI
and virtual reality. Despite advancements in motion quality and physical
plausibility, two pivotal factors, versatile interaction control and the
development of a user-friendly interface, require further exploration before
the practical application of HSI. This paper presents a unified HSI framework,
UniHSI, which supports unified control of diverse interactions through language
commands. This framework is built upon the definition of interaction as Chain
of Contacts (CoC): steps of human joint-object part pairs, which is inspired by
the strong correlation between interaction types and human-object contact
regions. Based on the definition, UniHSI constitutes a Large Language Model
(LLM) Planner to translate language prompts into task plans in the form of CoC,
and a Unified Controller that turns CoC into uniform task execution. To
facilitate training and evaluation, we collect a new dataset named ScenePlan
that encompasses thousands of task plans generated by LLMs based on diverse
scenarios. Comprehensive experiments demonstrate the effectiveness of our
framework in versatile task execution and generalizability to real scanned
scenes. The project page is at https://github.com/OpenRobotLab/UniHSI .
