A Generalizable Light Transport 3D Embedding for Global Illumination

摘要

Global illumination (GI) is essential for realism but remains computationally expensive. While per-scene neural methods lack generalization and screen-space approaches inherently suffer from view inconsistency, prior 3D neural rendering methods face a severe scalability barrier, restricting them to small, object-centric meshes. To overcome these trade-offs, we introduce a generalizable light transport 3D embedding that predicts global illumination directly from 3D scene configurations without rasterized or path-traced illumination cues, per-scene retraining or screen-space limitations. We employ a point-based representation to decouple our embedding from the original scene topology, then utilize a linear-complexity transformer to encode long-range light transport. This design scales to environments with millions of triangles, enabling the first generalizable GI learning on complex, high-fidelity indoor scenes, far beyond prior limits. To achieve this, we enforce a local query mechanism where rendering queries are processed independently under 3D supervision. This ensures constant complexity per pixel relative to scene size, yielding view-consistent and resolution-agnostic rendering without the memory bottlenecks typical of globally coupled attention. We further demonstrate versatility by re-targeting the encoder with limited fine-tuning, presenting preliminary results on spatial-directional radiance field prediction for glossy materials and validating transfer to downstream rendering tasks.