# Interact2Ar: Full-Body Human-Human Interaction Generation via Autoregressive Diffusion Models Source: [Interact2Ar: Full-Body Human-Human Interaction Generation via Autoregressive Diffusion Models]() Collection index: [llms.txt]() Data updated: 2026-03-31T05:00:04.048Z Authors: Pablo Ruiz-Ponce, Sergio Escalera, Jos\\'e Garc\\'ia-Rodr\\'iguez, Jiankang Deng, Rolandos Alexandros Potamias Published: 2025-12-22T18:59:50.000Z ## Abstract Generating realistic human-human interactions is a challenging task that requires not only high-quality individual body and hand motions, but also coherent coordination among all interactants. Due to limitations in available data and increased learning complexity, previous methods tend to ignore hand motions, limiting the realism and expressivity of the interactions. Additionally, current diffusion-based approaches generate entire motion sequences simultaneously, limiting their ability to capture the reactive and adaptive nature of human interactions. To address these limitations, we introduce Interact2Ar, the first end-to-end text-conditioned autoregressive diffusion model for generating full-body, human-human interactions. Interact2Ar incorporates detailed hand kinematics through dedicated parallel branches, enabling high-fidelity full-body generation. Furthermore, we introduce an autoregressive pipeline coupled with a novel memory technique that facilitates adaptation to the inherent variability of human interactions using efficient large context windows. The adaptability of our model enables a series of downstream applications, including temporal motion composition, real-time adaptation to disturbances, and extension beyond dyadic to multi-person scenarios. To validate the generated motions, we introduce a set of robust evaluators and extended metrics designed specifically for assessing full-body interactions. Through quantitative and qualitative experiments, we demonstrate the state-of-the-art performance of Interact2Ar. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. - [Human-human interaction motion generation on Inter-X (Full)](): Human-human interaction motion generation; Inter-X (Full); R-Precision (Top 1): 0.453. - [Human-human interaction motion generation on Inter-X Body](): Human-human interaction motion generation; Inter-X Body; R-Precision (Top 1): 46.9. - [Human-human interaction motion generation on Inter-X Body SMPL-X](): Human-human interaction motion generation; Inter-X Body SMPL-X; R-Precision Top 1: 0.447. - [Human-human interaction motion generation on Inter-X Hands SMPL-X](): Human-human interaction motion generation; Inter-X Hands SMPL-X; R-Precision Top 1: 0.402. - [Human Interaction Generation on Inter-X (test)](): Human Interaction Generation; Inter-X (test); R-Precision Top-3: 73.7. ## Original sources and implementation [Original paper]() [PDF]()