Kazakh-British Technical University

Radiance Cascades Compared to Unity's Standard Global Illumination Methods

This study empirically evaluates real-time global illumination (GI) methods within the Unity Universal Render Pipeline (URP), comparing Screen Space Global Illumination (SSGI), built-in Realtime Lightmaps (RTLM), and Radiance Cascades (RC).

• Radiance Cascades and Realtime Lightmaps ran at roughly 220 FPS in the isometric test scene, while Screen Space Global Illumination (SSGI) held near 105 FPS, and Radiance Cascades outperformed Realtime Lightmaps by about 5 to 10 FPS on average.
• SSGI's apparent efficiency in the realistic FPS-style exterior is misleading, because much of the indirectly lit geometry fell outside the camera view frustum and was never computed.
• Radiance Cascades handled dynamic emissive and moving light sources convincingly, but produced bloom-like overamplification under daylight and noise at close range.