Nvidia recently introduced the RTX technology, which should finally bring ray tracing in games. Ray tracing (raytracing) — method is not new. In relation to gambling talked about even 20 years ago, and the term with regard to computer graphics appeared in 1982, and since then in games method and have not appeared. But what is it all about?
Ray tracing is a method of creating three-dimensional models, which uses a principle similar to the real physical processes. That is for constructing an object, the system tracks the virtual trajectory of the ray from screen to the object.
In reality, we see not the objects themselves, and the light reflected from them. The exceptions are objects that serve as light sources. Ray tracing uses the same principles in a virtual environment.
The problem is that this method turns out extremely expensive from the point of view of requirements for hardware resources. If you use the usual methods of rendering the same color or transparency of a material object are set initially, and reflections and shadows are emulated including shaders and other tweaks, in the case of ratnasingam these characteristics are determined in the process of interaction of those virtual rays with the object, as in reality. It simply requires a colossal cost to the GPU even if some individual objects, not to mention the use of raytracing in games as the primary method of building objects.
For example, to construct images at a resolution of 1024 x 768 pixels by raytracing need to create 768 432 beam. In addition, each beam can be 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 are necessary polygons just need to have time to draw, in the case of raytracing each ray requires constant mathematical calculations, starting from the moment of its emission.
For this reason, raytracing has long been used where no work is required of the method in real-time. In the same game we just need the last one. Nvidia claims that did not previously exist graphics cards that have sufficient performance for the job. Now, sort is Volta, which have hardware to accelerate ray tracing. However, no details on this point. While it is not clear how actively the developers will be able to use raytracing, and that we, as players, get to the exit. But roughly understand it now. For example, in the video below.
It is expected by many Metro Exodus. It will be the first game AAA-class, using the RTX technology. But do you see in the video something strange? If you do not know where to look, most people don’t realize that this movie shows us expected the last couple of decades the technology. In fact, raytracing Metro will be used for some effects, global illumination. More specifically, for the model shading ambient occlusion and indirect lighting indirect lighting. In this classical rendering is not going anywhere.
Thus, we can conclude that, despite the fact that the introduction of raytracing games can be called a revolution, yet it is a very small and imperceptible revolution. Effects based on ray tracing we will see very locally. This will involve either lighting or reflection, including mirrors. Probably something more global can be seen in five years, maybe more.
I think it should also separately specify the point about Nvidia cards RTX and Volta. As you know, in sales there are only two models that use GV100 GPU is the Tesla accelerator V100 and more close to the people, but insanely expensive adapter Titan V. Undoubtedly, in the near future the market will see a massive graphics card with GPU Volta, but they are long enough to be in the minority. Especially considering that the current adapters Pascal most of the missing head. Yes, and the mining fever, which can damage the output innovations, and to dismiss is not necessary. So really enjoy ratnasingam in games in the next couple of years will be only the owners of new Nvidia cards? Not at all. Yes, Nvidia says about certain possibilities Volta GPU hardware to accelerate ray tracing, although details are still zero. But bring to the consumer market technology that is inaccessible to mass stupidity. So we have Microsoft DirectX Raytracing (DXR) is a set of new tools and methods for API DirectX 12. He will be responsible for hardware and purely software implementation of raytracing in games. The last option is interesting for all those who have no cards Volta.
However, there is a question about optimization and performance. Here is an example. Many of you know Nvidia HairWorks and TressFX AMD Hair that provide a more realistic render hair and fur. And these technologies are optimized for adapters GeForce and Radeon, respectively. At the same time on “foreign” cards they work fine, only stronger squander fps. A similar situation will happen with raytracing in games. The only question is how much the adapters are not related to the generation Volta, will squander fps when you activate the effects associated with ray tracing. This, incidentally, is another argument in favor of the fact that in the coming years retracing gaming in embryonic form.
As for AMD, the company has recently introduced its own engine ray tracing — Radeon Rays 2.0. Only it is based on the basis of API Vulkan. However, no restrictions in the generation of the GPU has not been specified.
To summarize, we can say that for most ray tracing in games in the coming years or will be unavailable due to a lack of powerful graphics cards, or pass by simply for the reason that the user will not notice and not understand, where it is used in a particular scene of a game. Although, who knows, maybe everything will be completely different.