ABSTRACT
In this chapter we present deferred normalized irradiance probes, a technique developed at Ubisoft Montreal for Assassin’s Creed 4: Black Flag. It was developed as a cross-console generation scalable technique and is running on all of our six target hardware platforms: Microsoft Xbox 360, Microsoft Xbox One, Sony Playstation 3, Sony Playstation 4, Nintendo WiiU, and PCs. We propose a partially dynamic global illumination algorithm that provides high-quality indirect lighting for an open world game. It decouples stored irradiance from weather and lighting conditions and contains information for a whole 24-hour cycle. Data is stored in a GPU-friendly, highly compressible format and uses only VRAM memory. We present the reasoning behind a higher achieved quality than what was possible with other partially baked solutions like precomputed radiance transfer (under typical open-world game constraints).
