Reward-Decomposed Reinforcement Learning for Immersive Video Role-Playing

Miao Wang, Yuling Shi, Yijiang Li, Yeheng Chen, Xiaodong Gu, Bin Li, Bo Gao, Wang Jun, Zengxin Han, Jingtong wu, Yaduan Ruan


Abstract
Text-based role-playing models can imitate character styles, but often fail to capture scene atmosphere and evolving tension, which are crucial for immersive applications such as VR games and interactive narratives. We study video-grounded role-playing dialogue and introduce EBM-RL (Eye-Brain-Mouth Reinforcement Learning), a decoupled GRPO-based framework that separates observation ( lt;perception gt;), reasoning ( lt;think gt;), and utterance generation ( lt;answer gt;). This design mimics the human See-Think-Speak process, enabling the model to ground dialogue in visual perception before reasoning and response generation. To optimize this See-Think-Speak process, EBM-RL integrates complementary rewards for scene-text alignment, perceptual-cognitive utility, answer faithfulness, and format consistency. Extensive experiments show that EBM-RL substantially outperforms text-only role-playing baselines and comparable-scale VLM baselines, while remaining competitive with stronger larger-scale VLMs on visual grounding and situational persona metrics. Moreover, EBM-RL demonstrates strong zero-shot transfer to out-of-domain VideoQA benchmarks without additional fine-tuning. We also release an open-source dataset for video-grounded role-playing dialogue.
Anthology ID:
2026.emnlp-main.346
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
7958–7989
Language:
URL:
https://aclanthology.org/2026.emnlp-main.346/
DOI:
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Cite (ACL):
Miao Wang, Yuling Shi, Yijiang Li, Yeheng Chen, Xiaodong Gu, Bin Li, Bo Gao, Wang Jun, Zengxin Han, Jingtong wu, and Yaduan Ruan. 2026. Reward-Decomposed Reinforcement Learning for Immersive Video Role-Playing. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 7958–7989, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Reward-Decomposed Reinforcement Learning for Immersive Video Role-Playing (Wang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.346.pdf