Radiance Cascades Compared to Unity's Standard Global Illumination Methods Global Illumination Methods

Abstract

This paper presents an empirical evaluation of real-time global illumination (GI) methods in the Unity Universal Render Pipeline (URP). Developers working with dynamic scenes must often choose between fundamentally different GI approaches while balancing performance, visual stability, and implementation complexity. To investigate these trade- offs, this study compares three methods available in URP environments: Screen Space Global Illumination (SSGI), built-in Realtime Lightmaps (RTLM), and the recently proposed Radiance Cascades (RC) technique. The evaluation was conducted across three representative game scenarios—a realistic FPS environment, an isometric scene, and a stylized interior—using controlled camera paths and dynamic lighting events. Performance metrics (FPS and frame time) were collected alongside qualitative analysis of visual artifacts. The results highlight practical strengths and limitations of each approach and provide developer-oriented recommendations for selecting GI techniques in URP-based projects.