It’s no secret that graphics cards are still not powerful enough to do ray tracing effectively. From there to DLSS or FSR and Ray Tracing currently go hand in handHowever, this relationship is not entirely perfect and has some associated issues which, although minor, are a sample of what technology has yet to do in this regard.
We still have a long way to go in visual game progress, so much so that it guarantees many years of visual improvements that graphics cards will have to be ready for. And everything indicates that all this is slowing down in recent years. That is, things are going slower than expected and some tricks had to be pulled for that.
DLSS and FSR don’t get along very well with Ray Tracing
One of the particularities of Ray Tracing is that it evolves in terms of the need for calculation according to the number of pixels of the image to be generated, which is why, in theory, scaling systems of real-time image like NVIDIA’s DLSS or AMD’s FSR exist, however, the reality is that they don’t and using these techniques completely destroys the ray tracing work.
We must start from the fact that the main advantage of Ray Tracing is that it allows us to reliably represent the effects of indirect lighting in real time. And this must be taken into account with each frame because the position of the objects changes, either by the action of the game, or by changing the position of the camera. And this point is important to understand why DLSS and FSR don’t get along with ray tracing, and yes, it seems counterproductive with all the marketing that we see, especially from NVIDIA, but all of this has an explanation and it’s a lot simpler than you think.
What is the problem?
When our graphics card applies a real-time scaling algorithm, we reconstruct the same image with a higher number of pixels. And what information does each of them contain? Well, the color value of each point on the screen, which is nothing more than the sum of its chroma and luminance. However, we have a problem and that is that we don’t know the color value of these extra pixels, so we use algorithms to find them so that the image is as reliable as possible.
Well, everyone knows the AI has shown this to be the best method, but the problem like everything is when incorrect data is added to the equation which ends up affecting the end result. And which are they? This is where the problem of temporality comes in, which consists in taking the color information that exists in the previous frames as an informative reference to build the current one. Let’s not forget that the lighting is dynamic in each frame and it must be taken into account that the light sources are in motion.
In other words, DLSS and FSR affect, affect Ray Tracing or at least the visual fidelity it intends to represent, but that doesn’t mean it reduces it to something useless, because without that algorithm , it is impossible to represent how objects generate shadows and they refract and reflect light faithfully with reality. What does all this tell us? Well, it’s very likely that we’ll see a version of these algorithms that will work better with Ray Tracing when the time comes, however, that’s another matter altogether.
