The transformative power of ray tracing has been proven in many different games, but perhaps the most impressive upgrades come from revamps of older, classic PC titles, and a recent mod for the original Quake frankly delivers amazing results. This isn’t so much a mod as it is a full-on RT remaster for one of the best PC games, courtesy of Sultim Tsyrendashiev, creator of path-trace versions of Serious Sam and Doom, and currently on RT Half-Life is working. Tsyrendashiev took over the Vulkan port of Quake from id Software’s Axel Gneiting and delivered something very, very special.
But first, how do you get your hands on the modded game? Simply download the required files from the VKQuake-RT Github page and merge them into the version of Quake you own according to the instructions on the page. It’s all relatively easy, but I recommend making a small change to the instructions. DLSS and FSR2 are supported – and both deliver great results overall, by the way – but the recommended DLSS 2.4.0 should be swapped out for the earlier DLSS 2.2.6. This will get rid of blurring issues that come with the newer version of Nvidia’s machine learning upscaling technology.
Beyond image reconstruction, this mod actually gives players two different RT implementations – a “classic” option that looks more like the original game, with some very nice ray tracing upgrades, alongside a full path tracer that radically changes the aesthetics of the game changes .
The classic renderer uses ray tracing for all primary geometry rendering, but the lighting is still processed through texture-based lightmaps as in the original game, meaning you get similar lighting and atmosphere with some intriguing RT effects: water surfaces are completely different, with RT reflections showing the whole environment. You also get RT-specific vision warping effects underwater. A really nice upgrade comes from the teleporters, which now portal-style show you the area you’ll end up in when traveling through.
The path tracing option offers a more radical transformation, using path tracing for all of the game’s lighting, completely replacing light maps and the other tricks Quake used to simulate what light looked like in 1996. Interior scenes are illuminated by torches and other small light sources that cast dynamic shadows from appropriate objects. As part of this system, all of the muzzle flashes from shots cast light and shadows, resulting in some pretty awesome Doom 3-esque moments in the dark. One of my favorite RT elements is the flash gun, which casts light the entire time the tracer’s surface exits the gun’s muzzle.
One of the biggest changes is the use of emissive lighting surfaces, which is only possible with RT. Teleporter pads with their little red lights cast light and shadows on nearby surfaces – confirming that colored lighting is also added, something lacking in the original Quake. Of course, lava is also a radiant light source that dramatically changes many scenes.
Even more impressive is that the sky itself is a radiant light source, so the iconic purple skybox now literally casts purple light on the world below, an incredible effect enhanced by the injection of truncated cone-aligned voxel nebulae, which can also be illuminated . The voxel grid is a bit coarse so you can see liasing in the volumetric fog, but it looks good enough and if you don’t like it you can turn it off separately in the options menu and go back to a generic distance fog – or no fog at all .
One of the more controversial changes, I’d say, comes from changing the game’s dangerous chemical pools: in the original they’re green/brown textures, but here they’ve turned into a super bright neon teal. Yes, it’s more clearly signposted as a hazardous material, but it does look a bit pretentious in some environments where I imagine a less intense and more subdued off-green would suit the mood better.
Other complaints? When the lights suddenly go out, there’s a prolonged afterimage of the lit scene that gradually disappears, which looks quite uncomfortable. Another problem concerns some surfaces that have a reflective element. Mirror lighting updates very slowly, meaning muzzle flashes from weapon fire will persist for some time. It looks very strange. The final issue is that scenes lacking a lot of direct light have a mottled appearance due to the limited ability of the denoiser to work in low light. So there are certainly some issues – but nothing to spoil the overall quality of the presentation. Finally, describing RT effects is no substitute for seeing them in action, so please check out the video embedded above.
In terms of performance, it’s interesting to see that both classic and path-tracing renderers have only a small margin of error in frame rate (you can always switch between them with a keypress, which may help explain why). and there’s not much to tweak the settings – so adjusting the resolution and thereby using image reconstruction techniques like FSR2 and DLSS2 is the way to go. Switching from native 4K to 4K DLSS quality mode on an RTX 4090 improves performance by nearly 100 percent, with a similar near-linear scaling when switching to performance and ultra-performance modes. Image reconstruction helps a lot here, to the point where an RTX 2060 in DLSS quality mode hits a locked 1080p60 with GPU headroom.
An RTX 3080 will get you up to 4K60 in DLSS quality mode, but even in FSR2 performance mode, AMD’s RX 6800 XT had some unfortunate frame-rate issues. At native resolution, the RTX 3080 offers twice the performance of the RX 6800 XT – not entirely unexpected with a path-tracing workload like this – but given the differences at native resolution, I really would have expected the 4K FSR2 performance mode to deliver 60 fps on the High end RDNA 2 cards so I think the AMD side of things might need some work.
In summary, this path-trace version of Quake is an incredible way to rediscover the game – it’s also fun for newbies and for those with an interest in RT in general. Put simply, a classic PC title gets a phenomenal upgrade and if you have the means I highly recommend checking it out.