LightOpt: Lights Optimization for Real-time Rendering

Modern game scenes often require hundreds of lights to achieve rich visual detail, yet evaluating many lights per pixel remains a major performance bottleneck in real-time rendering, especially on low-end platforms. We present a differentiable lighting optimization pipeline that automatically reduces the number of active lights while preserving the final rendered appearance. Our method jointly optimizes light parameters and dynamically performs light removal, merging, and insertion during optimization. We introduce two loss functions to minimize redundant light overlap and prevent under-illumination, and extend our approach to support Time-of-Day lighting. Experiments on production game scenes show that our method reduces lighting cost by 18–52% while consistently outperforming artist-authored light reductions in visual fidelity.