KIT graduate student Christoph Schied has released an open-source version of the Quake II engine that uses new Vulkan ray tracing tech and other tricks to pull off fully dynamic illumination, and it's something worth seeing.
This is a great example of what cutting-edge ray tracing and path tracing tech can do, and devs curious to see how it works can check it out on GitHub or watch a video analysis of the project (embedded above) recently published by Digital Foundry.
According to Schied, this version of Quake II (called Q2VKPT, for "Quake II - Vulkan Path Tracing") relies on Vulkan's relatively new hardware-accelerated raytracing features to run Quake II at nearly 60 frames per second with real-time full ray tracing and dynamic lighting.
"Q2VKPT makes use of a variety of techniques to adapt computationally expensive methods previously only used in the movie industry to games," writes Schied on the project's website.
"Using path tracing for fully dynamic lighting allows for a lot more detail in the shading of game scenes, naturally producing complex interplay of hard and soft shadows, glossy material appearances and perspectively correct reflections everywhere. Moreover, light can naturally flow anywhere, tying the scene together in the ways we would expect from the real world. Traditional approaches like precomputed lighting or coarse real-time raster approximations could never interactively reach this detail at a comparable resolution, since full storage of this lighting information would exceed any memory bounds."
For loads more technical details about how Schied pulled it off (as well as an explainer about how path tracing differs from raytracing, and why you should care) check out his website.