https://www.pcgamer.com/quake-2-with-ray-tracing-looks-stunning/

When it released in January, Q2VKPT offered a real-time ray traced version of Quake 2, demonstrating how a broad range of associated techniques could improve a 22-year-old game. Created by Christoph Schied, it used an RTX technique known as Path Tracing in order to create more lifelike lighting effects, and the results are impressive (there's a video at the bottom of the page).

Nvidia has been paying close attention, announcing today a collaboration with Schied (himself a former Nvidia intern) on Quake 2 RTX—a "purely ray-traced game". In other words, it rips out all traditional effects and replaces them with ray-traced lighting, reflections, shadows and VFX.