Why ray tracing is more important than you think – GND-Tech
Many gamers seem to believe ray tracing is nothing more than more sophisticated reflection technology, but they can hardly be more wrong. Ray tracing is not only the biggest leap in 3D gaming graphics technology for over a decade, and not only can it lead to dramatically improved immersion when used well, it can also lead to gameplay improvements and innovations. It’s a technology here to stay, it’s the present and the future, and in this article we’ll explain how while debunking other common misconceptions.
No, this is not an NVIDIA exclusive technology
Ray tracing is a feature of Vulkan and DirectX 12 Ultimate. Any graphics card that meets these requirements can perform ray tracing. This includes AMD’s RDNA 2 and Intel’s upcoming discrete graphics cards. Once you hit the RTX 3070 Ti and RX 6800 and below cards, AMD even begins to make strides in ray tracing performance, although the RTX 3080 and above reign supreme.
It’s much more than reflections
Of course, in a number of games the only thing ray tracing does is make the reflections more precise and incredibly more expensive. In such games, I wouldn’t even use ray tracing. I haven’t even used it on my RTX 3090. The recently released one Metro Exodus: improved edition is a preview of what ray tracing will do for most games in the future. Educate yourself and watch this video if you haven’t already.
As you can see, from a graphical point of view, this technology does a lot more than just enhance reflections. The ideal implementation is as demonstrated in the video: global illumination traced by infinite bounce ray, the most significant graphical improvement brought by the tracing of rays, as well as reflections, and also ideally shadows. When combined with quality PBR, it also makes textures and models look more realistic. When done right, the game world feels alive, interactive, and real, with every light and shadow behaving realistically. Games like this make games without ray tracing, especially those that don’t use global illumination, to seem totally static.
Another of the most interesting visual enhancements comes in the form of particle effects in a sci-fi game, though the particles of course use the same lighting and shadows. It is the most beautiful improvement that Quake II: RTX brings to the table, but imagine it in something like a Warhammer: 40,000 Game!
So it’s much more than reflections, but at the same time, it’s not just shiny, fluffy graphics. When it comes to visual immersion in games, one of the common things that spoils it is that the world is too static and not responding to player input. This is most often seen in the form of physical interaction (or rather lack of it), but it also applies to lighting and shadows where this is very common. For example, you use a flashlight in a game and it just doesn’t create dynamic shadows. A historically common occurrence in gaming, and when you see it it comes out like a sore thumb, especially if you’ve played games that aren’t guilty of this.
Interactive worlds, including interactive lighting, are highly beneficial for immersing the player, even necessary for certain types of games like horror and stealth (both first person and isometric and everything in between). But people often overlook the potential gameplay improvements ray tracing can bring, so let’s dive into that.
It can improve gameplay
DOOM 3 Heavily experienced with dynamic lighting and simply using it in gameplay, as shadows cast by enemies can often reveal their position. Global ray tracing illumination takes this to another level; in fact, even older and more primitive global lighting techniques that do not use hardware ray tracing have demonstrated this.
For example, global illumination and eye / HDR adaptation in Kingdom Come: Deliverance and Red Dead Redemption 2 allows the player, for example, to spot fires in the distance in low light situations, thus identifying people or camps where simpler lighting techniques would not allow you to see anything. It really is a life and death difference in a simulation game like Kingdom Come, where bandits tend to be more active at night and like to set up ambushes along the roads. Thanks to the overall lighting of the game, a keen eye can potentially get you to see them before blindly walking into your death.
With hardware ray tracing, it gets even better. There might be situations where the global illumination of Kingdom Come or RDR 2 is not far enough advanced to reveal a certain source of light that the material ray traced infinite bounce global illumination would reveal. This even extends to simpler scenarios like emptying a room in any FPS game; players like to hide in shaded corners in order to jump on you, but with proper use of ray tracing, they might be better illuminated by light sources, as the light travels and bounces more realistically, as shown in the Metro Exodus video from Digital Foundry above. These improvements aren’t exclusive to first-person games either; a correctly drawn and illuminated dungeon on a global scale would not only bring a great improvement in the atmosphere, but could again have a serious impact on the detection of the enemy (including the detection of the AI in a sufficiently advanced) in a dungeon robot or an RPG, and most types of games really.
Now imagine these improvements in a game like the first two Thief games, where it is absolutely vital to hear and see enemies before they see you. Thief, although these are late 1990s games with primitive lighting techniques, has a more complex mechanical light simulation than the vast majority of games due to its importance to gameplay. Hiding in the dark and spotting enemies and important items is a must. A proper implementation of ray tracing would make such a game infinitely more immersive, rely less on a HUD element and more on visuals and atmosphere to sneak in, and can even result in things like the player spotting a valuable item. difficult to see due to reflection or glow caused by lighting and reflection of the traced ray.
How about a daytime winter raid in a shooter, RTT or TBT? The sun is out and the sky is clear, but heavy snow and reflective ice on the ground can create a blinding atmosphere. This, combined with a game that simulates camouflage (or a multiplayer game where this happens naturally), would give characters dressed in white camouflage a particularly big advantage with proper ray tracing. How about a night raid in a tactical shooter, where you might want to avoid reflective gear as it can reveal your location if a light or the moon catches it?
Or maybe you’ll spot a target through detailed ray tracing reflection? And what about light reflecting glasses or binoculars in FPS games? In the Battlefield games that have this feature, scopes are basically just big spotlights visible during the day. This is a cheap knockoff which is actually unfair as it claims to reflect light even when no light should be reflected at all. With proper ray tracing, this feature can be implemented correctly, forcing snipers and observers to choose positions where sunlight will not reflect off their optics.
Identifying targets and planning around them isn’t the only gameplay improvement that ray tracing brings. Who knows what else the developers will come up with? Proper ray tracing implementation can add an additional challenge to a racing simulator during heavy rain when the sun is up, resulting in a wet and highly reflective track to the point where in some areas the sun will reflect strongly on the track, creating track lines that are impossible to see, making it harder to peak or even judge braking.
Performance is not a real concern
At most, it is a temporary concern. Ray tracing is quite expensive, but there have been so many recent performance enhancing technologies that can make up for the performance penalty. Additionally, the current generation graphics cards still struggle with ray tracing performance, but the next generation will be exponentially faster. That’s why the ray tracing takeover did not happen overnight.
Ray tracing like in Metro Exodus: Enhanced Edition requires some serious optimization to go along with it. We’re all familiar with NVIDIA DLSS and AMD FSR, and there’s Intel’s upcoming XeSS – these are absolutely necessary for a ray-tracing game; at least just FSR for now, NVIDIA’s proprietary and complex DLSS has minimal advantage at this point. More than that, we have mesh shaders that can lead to massive performance improvement, asynchronous computation, proper multithreading to remove bottlenecks and keep the GPU running, and more.
Metro is doing pretty well, with its extremely advanced ray tracing implementation that performs better than almost any other ray tracing game (most of which has much simpler implementations). Optimize the rasterized side of the game, make way for ray tracing. Then there are virtual reality games, for which eye tracking will soon be a standard, and games are expected to use it to dynamically render your peripheral vision content at a lower resolution, leading to Huge performance games in GPU strained scenes. Vulkan and DX12 prioritize optimization and efficiency above all else, so let’s use it.
Like any other gaming technology, there are games with both good and bad implementations. Too many people have left bad ray tracing implementations like Battlefield v color their perception of technology. The potential atmospheric improvements are both immense and obvious, as shown in the above Metro Exodus video from Digital Foundry.
What is less obvious to people are the potential gameplay improvements mentioned above. For the most part, they will become reality over time, as some can be experienced right now. Rather than dreading this technological improvement just because your computer can’t run it right now, let’s welcome this small evolution in game design, because evolution is exactly what this backward industry needs.