GenZI: Zero-Shot 3D Human-Scene Interaction Generation
Technical University of Munich
Given an arbitrary 3D scene, GenZI can synthesize virtual humans interacting with the 3D environment at specified locations from a brief text description. Our approach does not require any 3D human-scene interaction training data or 3D learning.
Can we synthesize 3D humans interacting with scenes without learning from any 3D human-scene interaction data? We propose GenZI, the first zero-shot approach to generating 3D human-scene interactions. Key to GenZI is our distillation of interaction priors from large vision-language models (VLMs), which have learned a rich semantic space of 2D human-scene compositions.
Given a natural language description and a coarse point location of the desired interaction in a 3D scene, we first leverage VLMs to imagine plausible 2D human interactions inpainted into multiple rendered views of the scene. We then formulate a robust iterative optimization to synthesize the pose and shape of a 3D human model in the scene, guided by consistency with the 2D interaction hypotheses.
In contrast to existing learning-based approaches, GenZI circumvents the conventional need for captured 3D interaction data, and allows for flexible control of the 3D interaction synthesis with easy-to-use text prompts. Extensive experiments show that our zero-shot approach has high flexibility and generality, making it applicable to diverse scene types, including both indoor and outdoor environments.
How It Works
GenZI distills information from vision-language model for 3D human-scene interaction. We first leverage large vision-language models to synthesize possible 2D humans interactions with the 3D scene by employing latent diffusion inpainting on multiple rendered views of the environment at location p using our dynamic masking scheme to automatically estimate inpainting masks. We then lift these 2D hypotheses to 3D in a robust optimization for a 3D parametric body model (SMPL-X) that is most consistent with detected 2D poses in the inpainted 2D hypotheses. This produces a semantically consistent interaction that respects the scene context, without requiring any 3D human-scene interaction data.
Zero-Shot 3D Interaction Generations
GenZI synthesizes more realistic 3D human-scene interactions and generalizes better across scene types, when compared to baseline methods that are either trained on indoor interaction data or base on 3D human estimation from a single RGB image.