Ray tracing is the hot new thing in video game graphics - so hot in fact that Sony's already announced the PlayStation 5 will be capable of it. So we're starting to see existing games with the tech enabled - with impressive results.
Digital Foundry has already reported on Half-Life 2, Minecraft and Crysis with ray tracing enabled. But I wanted to point to a couple of videos that show what Grand Theft Auto 5 and The Witcher 3 look like with ray tracing.
First up we have Grand Theft Auto 5 with ray tracing. You can really see the improvement in lighting in Rockstar's open world epic, particularly with the car parked under the freeway. I also love what it does to the house interior - the tables look fantastic!
Now on to The Witcher 3. Here, I think the ray tracing effect is more subtle than it is with GTA 5. But I can certainly notice a more realistic, almost subdued lighting effect with the tech enabled.
As Digital Foundry has reported, these ray tracing videos are possible because of a new extension currently in development for the powerful post-process injection tool, Reshade, created by modding veteran and Nvidia Ancel contributor, Pascal Gilcher.
"Reshade works by hooking into DirectX, accessing the data contained in the depth and colour buffers to accomplish a range of post-process effects, including SMAA anti-aliasing, screen-space reflections, depth of field and colour tints to name but a few. A new ray tracing feature is now available in alpha builds - and strictly speaking, this adds a new layer of global illumination derived from path tracing. It's not a full fat implementation as we saw in Minecraft, but it can have a transformative effect - particularly on titles like the original Crysis, created at a time when the way games were lit was somewhat naïve compared to modern day implementations."
It would be misleading to suggest the GTA5 ray tracing video offers a glimpse at what a next-gen GTA game might look like (Red Dead Redemption 2 without ray tracing looks better than GTA5 with it, for example). The filter is fairly limited, and only supports lighting and ambient occlusion. It also can't trace light from anything that isn't on-screen, so you end up seeing some weird effects. (The video below from Digital Foundry explains all this well.)
This is why, for now, the filter seems to work best on older games, which used basic lighting. (Older games are also a better fit because even with the limitations, the ray tracing is super taxing on GPU.)
Still, it's fun to see what this next-gen graphics tech does to our favourite games, and imagine what powerful PCs, the PS5 and the next Xbox will be capable of.