Modder implements path tracing for all lights in Quake II and hits 60fps

A modder has managed to implement a well-functioning path tracing implementation in Quake II. Using a Geforce RTX video card and a filtering technique that improves efficiency, he manages to ensure that all lighting effects are path traced and the game remains playable.

The modder has incorporated the path tracer into the Q2PRO client, a client that, among other things, ensures that the game remains compatible with more modern hardware and software. The tracer is also on GitHub for anyone who wants to look under the hood. It’s about 12,000 lines of code that replace the entire graphics code of the 1997 original.

The result is impressive: warm, glowing light effects with soft edges, the light from wall lamps bounces off the floor, but inside the core of that reflection, the reflection of those lamps is clearly visible. It’s a stark contrast to see such a new graphics technique working side-by-side with textures and models from 1997. The German modder chose Quake II because it has a long history with mods and would therefore make a good sandbox for these kinds of experiments.

For those who want to know more about the project, the German, Christoph Schied, has put an extensive website with information online, complete with two demo videos, several screenshots and a download for those who want to try it for themselves. An RTX video card is required. Schied himself used an RTX 2080 Ti. Path tracing is a technique similar to ray tracing, but more processor-intensive. An example of a more modern game that uses ray tracing is Battlefield V.