By conditioning on intrinsic image properties (albedo and shading) extracted from both photos and 3D renders, you can achieve photorealistic relighting with full PBR lighting control while staying fast enough for practical use.
PIXLRelight is a fast neural relighting method that lets you change lighting in photos using physically-based rendering controls. It decomposes images into intrinsic components (albedo, shading, residuals) and uses these to condition a transformer model, enabling realistic lighting adjustments in under 0.1 seconds per image without per-image optimization.