AI 拍情绪戏,终于有人管住它的审美跑偏
让 AI 生成视频时,「情绪对不对」一直是个没人说得清的标准:画面清晰、动作流畅都有客观分,但「这段该悲伤还是该紧张」只能靠人主观打分,AI 很容易为了讨好分数而跑偏。这篇提出一套自我进化的奖励校准机制:训练过程中,AI 自己从过往的评分记录里判断哪些情绪线索可靠、该信多少,再动态调整各项指标的权重——比如某个镜头里脸部表情比肢体动作更关键,就多给脸部打分。在多个视频生成模型上,它比固定奖励和人工反馈都更稳。它不是你明天能用上的东西,但它是「AI 懂情绪」这条路上少见的、不靠人海战术的解法。
📄 原文摘要(英文)
Group Relative Policy Optimization (GRPO) has advanced generative model post-training in verifiable domains such as code and mathematics, but evaluating video quality, especially emotional expression, often depends on subjective aesthetics and has no uniquely correct target. Existing approaches typically rely on fixed rewards for visual quality, motion quality, and text alignment that poorly capture emotional intent and can invite reward hacking, while RLHF is difficult to scale and subject to individual aesthetic differences that complicate the calibration of facial, body motion, and chromatic cues across narrative contexts. We introduce EmoReward, a new self-evolving training mechanism that distills evidence reliability from reward traces collected during an actual training run to adaptively guide multi-reward weight allocation in subsequent training by determining which emotional evidence to trust and how much to weight it. EmoReward first plans specific grounding cues from the emotional prompt to guide evaluation, then uses heterogeneous signal primitives to score the generated video during the act stage. Reflective Reward Gating calibrates their contributions through instance-level gates for phase, face confidence, conflict, and subtlety, then renormalizes weights over the active set to produce the sample's fused reward. RewardMemory then estimates each primitive's reliability from rollout scores and outcomes within each emotional regime in the finished training run, then fixes bounded multipliers that calibrate fusion weights in the next training run without updating reward models. Experiments on HunyuanVideo 1.5 show improvements across multiple RL algorithms and compare EmoReward with other agentic reward methods under SAGE-GRPO. Ablations and transfer experiments on SD 3.5 and FLUX further support adaptive reward calibration for visual generation.