VMem: Consistent Interactive Video Scene Generation with Surfel-Indexed View Memory

We propose a novel approach for long-term autoregressive scene generation in the form of a camera-conditioned video stream.Existing methods either rely on explicit geometry estimation in inpainting-based approaches, which suffer from geometric inaccuracies, or use a limited context window in video-based approaches, which struggle with long-term coherence.To address these limitations, we introduce Surfel-Indexed Memory of Views (SIMView), a mechanism that anchors past views to surface elements (surfels) they previously observed.This allows us to retrieve and condition novel view generation on the most relevant past views rather than just the latest ones.By leveraging information about the scene's geometric structure, our method significantly enhances long-term scene consistency while reducing computational overhead.We evaluate our approach on challenging long-term scene synthesis benchmarks, demonstrating superior performance in scene coherence and camera control compared to existing methods.