Nvidia introduced RTX technology, which brought ray tracing to games, but it is not a new method. It could regard the games about 20 years ago, but the term appeared on computer graphics in 1982, and the method of games has not appeared since then. So, what’s RTX?
RTX meaning the method of building three-dimensional models that uses a principle similar to real physical processes. The system traces the trajectory of a virtual ray from the screen to that object to build an object
In reality, we do not see objects by themselves, but light reflected from them. The exceptions are objects which themselves serve as light sources. The ray-tracing method uses approximately the same principles for the virtual environment.
What is RTX in gaming?
The problem is that this method turns out to be extremely costly in terms of hardware resource requirements. Whereas with conventional rendering methods, the color or transparency of an object’s material is set initially, and reflections and shadows are emulated through shaders and other tricks. In the case of raytracing, these characteristics are determined in the process of interaction of those virtual rays with the object, just like in reality. This requires a tremendous expenditure on the part of the GPU even in the case of some individual objects, not to mention the use of raytracing as the main method of building objects in games.
For example, to build an image with a resolution of 1024 x 768 pixels using raytracing – it is necessary to form 768 432 rays. At the same time, each ray can be both reflected and refracted, which ultimately leads to an increase in the number of traced rays several times. And if in the case of conventional rendering methods necessary polygons just need to have time to render, in the case of raytracing each ray requires constant mathematical calculations, starting from the moment of its emission.
This is the reason why raytracing has long been used where it works in real-time is not necessary. In games, we need the second method. Nvidia claims that previously there were no graphics adapters with sufficient performance for such work. It is not clear yet how actively game developers will be able to use raytracing and what players will get in the output. But roughly, we can already understand it. For example, from the video below.
What does RTX stand for
The introduction of raytracing into games can be called a revolution, but so far, it is a very small and unnoticeable revolution. We will see effects based on raytracing very locally. It will be about either lighting or reflection, including mirrors. Probably something more global will be seen in five years, or even more.
What are RTX graphics cards?
It is also worth to mention the point about Nvidia RTX technology and Volta cards. As you know, there are only two models that use GPU GV100 on sale – Tesla V100 and more close to the people, but insanely expensive Titan V adapter. Undoubtedly, mass graphics cards with GPU Volta will appear on the market soon, but they will be quite a long time in the minority. Especially because current Pascal adapters are enough for the majority.
Yes, and mining fever, which can spoil the release of new products should not be discounted. So, will only owners of new Nvidia cards be able to enjoy raytracing in the games in the next couple of years? Not at all. Yes, Nvidia says about some possibilities of GPU Volta hardware accelerate ray tracing, although the details are zero. But to bring to the consumer market a technology that is not available to the masses is silly. Therefore, we have Microsoft DirectX Raytracing (DXR) – a set of new tools and methods for the DirectX 12 API. It will be responsible for both hardware and software implementation of raytracing in games. The latter option is just interesting for all those who will not have Volta video cards.
What does RTX graphic will do?
There is a question about optimization and performance. Here is an example. Many people know Nvidia HairWorks and AMD TressFX Hair technologies, which allow a more realistic rendering of hair and fur. And these technologies are optimized for GeForce and Radeon adapters, respectively. At the same time, they work fine on “foreign” graphics cards, but it only loses more FPS. The same situation will be with raytracing in games. The only question is to what extent non-Volta-generation adapters will lose FPS when raytracing-related effects are activated. This, by the way, is another argument in favor of the fact that raytracing in games will be in its infancy in the coming years.