A convincing fake GI that costs almost nothing is a great example of the clever "cheats" in game development. Jussi Kemppainen, Lead VFX Artist at Remedy Games, who we previously featured for his solo-developed vehicle combat project Drivers of the Apocalypse, has shared how he implemented a lightweight, real-time fake GI solution for the game.
The warm sunset glow wrapping beneath the car isn't baked lighting, a probe volume, or a reflection capture. Baked GI is impractical in Drivers of the Apocalypse: vehicles in the game can be hijacked mid-battle and flung across five different biomes. Instead, the system uses a rolling 16x16 grid of ambient light probes that store spherical harmonics to encode the surrounding light, with the grid looping toroidally so only newly wrapped probes need recalculating. The developer explained it in more detail in the thread:
