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RODERICK VAN DER STEEN – Lead Lighting Artist: Lighting is crucial to the look and feels and the overall visual experience of any form of art or entertainment. I will start with some history, so people can understand where we came from. The base lighting (direct and indirect) at
Guerrilla has historically been about getting the best bang for your buck in terms of performance vs. memory vs. quality – the latter always being the leading factor. "
"For Killzone Shadow Fall (PS4, 2013) we used per-pixel lighting (spot, omni, directional, area light disk, rectangular, and point/sphere with an option for textured area lights). We used a custom BRDF for direct lighting, spherical harmonics for dynamic lightning, and directional lightmaps for the indirect lighting (using all the previous tricks we learned, but this time also occasionally using half float to get a lot better range and HDR-like levels for our baked lighting.)
For Horizon Zero Dawn (PS4, 2017) we used per-pixel lighting using all the Killzone Shadow Fall tricks, but using GGX as the BRDF of choice to give our materials a wider and more accurate range of material expression. We also added a dynamic skylight to the mix, which lights everything based on the sky color from all angles." ....
"For our indirect lighting solution, we used irradiance volumes. You can think of them as multilayered lightmaps, where each pixel of each layer has a 3D location in space, and multiple directions based on probe positions. We used this for both our static and dynamic objects, giving us a fully unified way of doing indirect lighting for all objects...
It also allowed us to have a dynamic time of day. We baked the indirect lighting of our sunlight at 4 times of our day/night cycle, to 4 different sets of irradiance volume textures, which we then blended overtime to give the illusion of having accurate indirect lighting across all times of the day."
"Our renderer is built into our engine and works by voxelizing the world and baking information like albedo, normal data and translucency into a voxel cache, which is then re-lit for each time of day and the static indirect bake. This way we get material information and correct color bounce across the game."
