CD Projekt RED confirmed during this year’s GDC that Cyberpunk 2077 will receive patch 1.62 on April 11, and that this update will add RT Overdrive modea setting that will significantly improve the game’s graphical quality through use route tracing. With this patch, Cyberpunk 2077 becomes the fourth game available on PC, along with Minecraft, Portal and Quake II RTX, to use this rendering method.

I think before we get to the changes that RT Overdrive mode will offer, it is important to analyze the differences between path tracing and ray tracingtwo technologies that are practically analogous to many, but which deep down present differences in such important nuances that they deserve to be considered and appreciated in a different way.

It can be said that in general, these two technologies have a goal to more realistically recreate the interactions of light beams in each scene. Both can produce graphics with a quality level higher than what we would get from a classic raster process, which uses classic texture maps for lighting and shading and reflections of the screen space. However, as we hypothesize, they also have important differences, which we will explain below.

Ray tracing vs path tracing

Ray tracing projects rays in all directions from various locations, tracing the path of light and its interactions with various targets by calculating errors and collisions and the possible reflections resulting from such collisions. This allows you to create more realistic images with less noise, but it also means a high cost in terms of performance.

When we talk about path tracing, we can say that generally speaking, it is a simple evolution of ray tracing, because both technologies have the same goal and differ only in the way they achieve it. This technique it can fire a large number of beams per pixel simultaneously which behave randomly, which greatly improves image quality.

Despite this larger number of rays, path tracking can handle complex scenes where a large number of objects coincide. in a very efficient waybecause it uses integral equations in the whole process, which help to solve complicated situations in an optimal way using the obtained samples.

These equations form it is not necessary to use all rays to generate pixels in the final scene. It also doesn’t count as many reflections as ray tracing, because it’s possible to set limits on the total number of reflections that end when the light source is reached or when a set limit is reached.

On the other hand, this technology too select those ray paths that are considered “ideal” taking into account key aspects such as camera position, light sources and reflection. Starting with everything we said, the number of samples per pixel is adjusted, and in this way it is possible to refine the quality of the image.

That means it’s part of a very complex process where we can find thousands of rays first, but that thanks to algorithms and integral equations, it is simplified to achieve a realistic result more efficientlywhich reduces both the number of samples used and the amount of reflections.

Ultimately, this has a very positive impact on image quality the first interactions and reflections of light are most noticeable when it comes to adding color to the scene. However, it is also important to note that in the scenes where we have lots of reflections and refractions Ray reflections are more important and in these cases ray tracing achieves better results, although you can also adjust the path tracing algorithm to increase the amount of reflections used in the patterns to compensate.

in both techniques a final noise reduction process needs to be applied to the image, since the result we get after using ray tracing or path tracing is an image that can look quite “dirty”, as you can see in the attached video. The noise in the image will largely depend on the number of rays (total number of samples) that were used to generate it. Obviously, the greater the number of rays and reflections, the higher the image quality, but also the greater the impact on performance.

GeForce RTX 20 and higher graphics cards speed up ray tracing and path tracing through RT coresand use tensor kernels for the final noise reduction process. The Radeon RX 6000 and RX 7000, on the other hand, use ray tracing accelerators for key tasks associated with both technologies.

How Cyberpunk 2077 will improve with path tracking

Now that you’re clear on the differences between ray tracing and path tracing, it’s a good time to start seeing the improvements that patch 1.67 will introduce to Cyberpunk 2077. As we said, this patch will bring a new graphics mode called RT Overdrive, which will use road layouts for improve lighting, shadows and reflections. This is the official description offered by NVIDIA and CD Projekt RED:

• More realistic lighting with NVIDIA RTX Direct Illumination (RTXDI)which will make every light source in the game generate accurate and realistic light, able to directly and indirectly affect all elements in the game, as well as generate more realistic shadows and scenes with accurate colors.
• Both lighting and reflections will now have multiple bounces (only one reflection has been generated so far) which will improve the accuracy, realism and quality of both effects. This should translate into better quality indirect lighting that more closely matches the reality of each scene, and more accurate and fine-tuned reflections.
• Reflections now render in full resolutionwhich will give them better sharpness and higher quality compared to crazy mode, where they already looked amazing, but without the classic problem of “mirror” mode, because it will still distinguish perfectly between matte surfaces and reflective surfaces.
• lighting physics improvements, making it no longer necessary to resort to techniques such as ambient occlusion to create realistic scenes where a large number of objects of different sizes coincide. The difference this can make is huge, especially in the interior.

With RT Overdrive mode activated Cyberpunk 2077 will work with a total of 635 flash operations per pixel, which is more than double the amount used in insane mode. Obviously, this will have a significant impact on gaming performance, so it will be necessary to compensate by resorting to DLSS2 or DLSS 3 in case we have a GeForce RTX 40. In this case, frame generation will play a key role in terms of improving fluidity.

NVIDIA has also confirmed that the game will be optimized to take advantage of the technology Shader Execution Ordering (SER), which is exclusive to the GeForce RTX 40 and can significantly improve performance. I look forward to testing the game with different GPU settings when this patch is released and will post a detailed article telling you what to expect if you enable RT Overdrive mode.