What is ray tracing and do we need it in games. In this article Battlefield V, Control, GeForce, Metro Exodus, Minecraft, NVIDIA, RTX ON, video cards, Games, ray tracing, we will talk about the technology of ray tracing in games, how it works, which gives the gamer and also reflect on whether it is useful at all. The answer to this question, by the way, is not as obvious as it seems at first glance. But first things first. The reading time for this article is 8 minutes.
- About technology
- How ray tracing effects games and performance
In the gaming industry, ray tracing technology appeared on NVIDIA RTX series graphics cards, which the company introduced in August 2018. These adapters work on the Turing architecture, named after the English mathematician Alan Turing. Support for ray tracing has become a feature of this series, which at the moment is the most productive among all the families of NVIDIA graphics cards.
What kind of technology is this and how does it work? In real life, we see things around us due to the fact that the rays of light are reflected from them and fall on our retina. Ray tracing technology (which is abbreviated as RTX, like the line of video cards) provides for the same process, but already in games. Tracing algorithms calculate the trajectory of each ray of light from the object to the camera, and the video card displays a picture based on these calculations. At the same time, surface properties are taken into account: some materials reflect light better, others worse, glass refracts rays, etc. This makes it possible to accurately transmit the illumination of objects, their shadows, refractions, light scattering and generally give the image on the screen a more realistic look, than with conventional rasterization (the existing way to create images for games).
The catch is that for the operation of trace algorithms, large computational resources are needed. For example, one frame of an animated film using ray tracing technology can be rendered for a day or more. In games, of course, this approach is not suitable – here it is necessary for real-time to issue a comfortable number of frames per second (preferably, at least 40 FPS). Therefore, now in games a hybrid model is used, where ray tracing is applied only to individual objects. And then, for this, we need the most powerful video cards.
At the moment, these are only the NVIDIA RTX series graphics accelerators. They have special kernels that are responsible for tracing, which allows you to display the speed of this procedure to an acceptable level. Even on the most powerful NVIDIA graphics card of the previous generation – GXT 1080 Ti – the processing speed of trace algorithms is about six times lower than on RTX video cards. Company AMD is also working on the technology, but the market of graphics cards with support for tracing until they came (maybe it will happen this year). Also, ray tracing requires Windows 10 and a special extension for DirectX 12 that supports algorithms at the software level.
Ray tracing is not only for gamers. For game developers, it simplifies the process of creating levels and environments. Without this technology, all the lighting effects in games have to be created manually. For example, if a lamp is lit at the level, then it is necessary to register the reflections of rays and shadows from it. You do not need to do this with ray tracing – everyone must process the algorithms in automatic mode. In addition, tracing can work with sound, creating much more realistic audio for games.
How ray tracing effects games and performance
Although RTX technology appeared on the market a year and a half ago, the list of games with its support is still not very large. Now, taking into account the projects in development, there are about 30 of them. Among the AAA titles that are already available for purchase, we will single out Battlefield V, Shadow of the Tomb Raider, Metro Exodus, Control and Stay in the Light. It is clear that in the future there will be more such games, but it’s too early to say that ray tracing is being implemented everywhere.
The main thing that this technology brings to games is the greater realism of lighting. Which, incidentally, is not always useful. For example, an important part or quest item may appear in the shade, and the corners of a room with one light source may be too dark. But these are rather exceptions. Ray tracing in the lion’s share of cases has a positive effect on image quality and its realism. Shadows can move dynamically, more objects are reflected in the water, fire in the dark dazzles a little, as it should, and the picture as a whole looks livelier and looks more like what the player would see in real life.
You can see what ray tracing provides using Minecraft as an example. Yes, it has deliberately primitive graphics, but for demonstration of tracing this is just a plus – the difference in a picture with tracing and without it is much more noticeable. You can verify this in the following video:
Another game in which the difference between the presence of trace and its absence is clearly visible is the classic Quake II shooter. It graphically shows how a picture changes qualitatively using trace algorithms:
But if we move on to more modern (or more advanced in terms of graphics) games, the difference becomes not so noticeable. The fact is that neither in Quake II nor in Minecraft, the developers initially engaged in lighting realism as such. In the first case, because 23 years ago the technologies and capabilities of the developers were “a bit” more modest, and in the second – in this game, this aspect is far from the most important. But when we take games where the emphasis is on the quality of the graphics, the differences are more difficult to notice. Take a look at Shadow of the Tomb Raider, for example. RTX technology, of course, adds realism to the picture: dynamic shadows from moving light sources appear, where necessary, they soften and look more natural. But, on the other hand, the difference is non-cardinal:
Another video from Shadow of the Tomb Raider. It also demonstrates that with tracing enabled, lighting looks more realistic, but in some places, it’s hard to notice:
There is also a difference between trace modes. But often it is either not noticeable at all, or the differences are so small that they can be neglected. This is clearly seen in the screenshot below:
Let’s take a look at Battlefield V – the example of this game clearly shows how tracing improves reflection in the water:
The difference in the picture using ray tracing and without it is quite noticeable. But on the other hand, in these games, even without tracing, everything is fine with lighting. Let it be a little less realistic, but it also looks great and the difference in the presence of tracing and its absence is not so striking. Especially if the player is focused on the passage of the plot or the battle with the enemy, and not on the search for differences in lighting. And here we come to another important question: how does tracing affect performance?
Since the processing of trace algorithms requires a large amount of computation, an additional load is applied to the video card (and it is very significant). And this, in turn, reduces the number of frames per second. Depending on the power of the video card, you can choose one or another mode of trace quality: ultra, high and medium. Depending on the selected model, a different number of objects will be processed (the higher the quality, the more).
How much does this affect FPS? TechSpot reporters understood this. They tested popular ray-tracing games on all of the latest NVIDIA graphics cards. On their test computer, the latest drivers, the latest updates of games and the operating system were installed. For the test, all picture quality settings were set to maximum, and the resolution was selected at the level of 1440 p. Journalists noted that on average the number of frames per second fell by 30-50% depending on the game and the quality of the trace Battlefield V Control GeForce. But at the same time, the FPS values mainly remained within the comfortable perception.
So, Battlefield V on the most powerful graphics card RTX 2080 Super gave 111 fps without tracing, 76 FPS – with low quality tracing and 57 FPS – with high. On the budget version of the RTX 2060 Super, the indicators were as follows: 86 FPS without tracing, 61 FPS with low trace quality and 45 FPS with ultra-high quality. That is, even with a not-so-expensive graphics card, this game can be comfortably played with the highest trace quality.
True, in other games the results were slightly worse. For example, in Metro Exodus RTX 2060 Super gave out at ultra-high quality 35 fps, and in Control only 26 FPS. And if the game at 35 fps can still be called comfortable, then about 26 FPS this can not be said for sure Battlefield V Control GeForce.
Ray tracing in games is still a young technology that is taking the first steps in the industry. So far, its presence or absence does not particularly affect the quality of games. Rather, it is a fashionable chip, without which, for now, you can completely do. But this will not always be. This technology greatly simplifies the game development process, so in the future, it will be used more often, and gradually move away from old models of working with light. It is clear that this is not a matter of the coming years, but nevertheless, the vector of industry development is obvious. By the way, according to representatives of NVIDIA, Battlefield V Control GeForce the first AAA game, which will definitely require a graphics card with trace support, may be released in 2023.
Now the spread of this technology is hindered by several things. Video cards with its support are expensive and one cannot say that it is much more productive than the adapters of the previous generation. Also, while there are not very many games with its support, and people do not quite understand why now overpay for the latest generation video card. Enabling tracing causes noticeable subsidence of FPS, albeit almost always uncritical, but still noticeable. At the same time, the level of realism of the picture, although it is increasing, is not straightforward, so as to how. Therefore, in the next few years, it will not be mainstream. Although the fact that eventually tracing will become a generally accepted standard, there is no doubt. You just have to wait.