Scale3D: Autoregressive Modeling for Large Outdoor Scene Generation

We present Scale3D, an autoregressive model for generatinghigh-quality outdoor 3D scenes at scale. Scaling 3D generation to vastenvironments like city blocks usually degrades local geometric detailsas the layout expands. Scale3D decouples this problem into a two-stageprocess. A causal autoregressive model x001Crst plans the global layout bypredicting scene chunks over a 2D spatial grid. A masked autoregressivemodel then synthesizes the actual 3D geometry within each chunk. Wereconstruct these local structures using a 3D chunk-based VAE designedto preserve sharp edges and high-x001Cdelity surfaces. We also introduce apipeline that extracts spatial relationships directly from geometry, al-lowing users to control complex scene layouts via simple text prompts.Unlike patch-based dix001Busion models that struggle with boundary arti-facts, Scale3D maintains long-range spatial coherence across expansiveoutdoor datasets while rendering detailed 3D structures.