Why Video Diffusion Models Break Physics: Researchers Trace It to RoPE Spatial Anchoring and Fix It by Rescaling RoPE Frequency
The work presents an interpretability study of the "motion planning" process in text-to-video diffusion models, finding that excessive spatial attention decay induced by RoPE in self-attention makes early candidate regions lock prematurely onto physically implausible positions, and proposes a lightweight architectural change that merely rescales RoPE frequency across denoising steps, improving physical commonsense in both training-free and training-based experiments.