The word Ray Tracing was unknown to PC users, as it was a word more closely related to the world of professional 3D animation. Since talking about Ray Tracing was talking about complex systems consisting of several computers in parallel, occupying an entire room. Also, the RTX 40 has a secret inside which will cause two things in the future. The first is to differentiate itself more from AMD in this aspect in terms of performance, the second is that it will make it even easier to adopt ray tracing in games.
Soon it will be five years since the launch of the RTX 20, and the launch of a commercial game with only Ray Tracing has not happened. Thus, a certain prediction of NVIDIA did not come true. Looking at it cold, the same time elapsed between the RTX 20 and the RTX 40 as between the first Voodoo Graphics and the original GeForce. In other words, the evolution in terms of graphic architectures is less today than at the end of the last century.
What’s the secret of the NVIDIA RTX 40?
Since we are going to comment on a patent and these are intended to fix an existing problem, the first thing we need to do is explain what that problem is. The most basic idea of the Ray Tracing algorithm is that for each pixel in the image, a ray is drawn from the viewer’s perspective, and then it is determined whether there is an object in that pixel or not, and if there is, it is painted in a certain color and so on.
However, its visual advantage lies in the fact that we can also summon lightning from objects and this is where the big problem comes in. If there is no boundary condition, the rays will bounce around the scene indefinitely, and the complexity of the algorithm will grow infinitely, not being able to run and freezing the computer.
It is therefore necessary to set a series of termination conditions:
- The beam exits the scene into a vacuum, so its corresponding instance is removed.
- A certain number of bounces per ray is allocated, once this number is reached, the ray is destroyed.
- Each object is assigned a refraction quotient ranging from 0 to 1, a 1 is mirror material, a 0 is literally a black hole. When said report in a radius is too low, then it is destroyed.
- By determining the distance between two objects, if it is too large, then the beam is destroyed.
Well, the secret of the RTX 40 concerns precisely the last point.
Application on current graphics cards.
Once we have specified the problem, we need to talk about the solution. What happens is that in the case of Vulkan and DirectX APIs, used for games. In these, the rays are not executed automatically, but must be explicitly called by the game code. Thus, one can suddenly find scenarios where the Ray Tracing totally or partially disappears in order to maintain a high frame rate .
The secret of the RTX 40’s RT Core
Well, in the third generation of RT Core and if we pay attention to a certain patent released last year by NVIDIA, chances are that said unit will receive a significant improvement. These would be two new units that will be used to speed up ray tracing.
- The first is able to determine the distance between the camera and an object or between two objects. This saves power to the rest of the graphics chip in this task. So if the second object is too far from the first one the beam is summoned from, then the beam that would go from unit to unit is marked as throwable Another thing you can do is decrease the power of the light source in order to improve the representation of shadows.
- As for the second unit, it would be responsible for determining if it summons more rays depending on the conditions of the scene.. That is to say that those which have been discarded under the effect of the distance, can then be recovered in other objects. So, in the end, it’s all about making smart use of the resources we have.
All of this we did not invent, but belongs to the information of an NVIDIA patent titled ADAPTIVE RAY TRACING ADAPTED TO SHADOW RENDERING from where the whole process is described and from where we took the image below.
NVIDIA’s goal with the RTX 40 is to leave AMD out.
NVIDIA’s idea would be none other than to automate Ray Tracing and therefore make all games compatible without the need for patches of any kind by programmers. This would give them a huge advantage over AMD, since eThis technique can only be performed on your graphics cards.
If we add to this that from frame to frame the vast majority of objects in the scene do not vary their distance from each other since they are static, then the system has a much easier time assigning which rays are invoked and which are not. Either way, the ultimate goal is for games to get higher frame rates on NVIDIA cards compared to their direct rivals.
By the way, although it is less reliable, it is said that NVIDIA could increase the ratio of RT cores from unit per SM to unit per sub-core i.e. cquadruple its amount compared to the current RTX 30. Although take it rather with tweezers, in any case, if this is the case. It would be a major punch on the table against its rivals and a step closer to the mass adoption of Ray Tracing in games.
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