Forza Motorsport in 4K / 60 FPS / Ray Tracing: concessions seen by Digital Foundry | Xbox One

Forza Motorsport will be available in 4K and 60 FPS on Xbox Series X and in 1080P and 60 FPS on Xbox Series S, all with active ray tracing during racing. But how is that possible when it would require war machines to reach such a level on PC? Digital Foundry researched the case and analyzed the trailers released by the developers, highlighting some very interesting details.

Anti-aliasing different from MSAA x4?

The first technical information about the rendering of Forza Motorsport is impressive as very few games manage to reach such levels. The developers have about a year left to make optimizations, but the technical specialists at Digital Foundry have found the tricks that enable Turn10 to achieve the rendering they claim.

On Xbox Series X, the game will be available in 4K and 60 FPS with active Ray Tracing reflections while you play. The gameplay, which was shown at the Xbox conference, ran on PC, but Turn10 later clarified that the demo was also tested on Xbox Series X for similar rendering. We are therefore waiting to see this version later, but you can watch the videos on your 4K TV while you wait to get a preview of the playback on PC.

Digital Foundry points out that even very advanced PCs have trouble handling reflections in Ray Tracing when a game is running at 60 frames per second in 4K. So how would Turn10 achieve this on Xbox Series X? The answer lies in the details.

In the past, Turn10 has always modeled itself after the native resolution of consoles with MSAA 4x (Multisample anti-aliasing), an anti-aliasing technique that uses sampling only at the edges. But with this new Forza Motorsport, the developers have apparently chosen a different strategy, if one is to believe the videos that the developers have shared. By slowing down certain broadcast sequences, we realize that anti-aliasing is not applied to certain elements of the body, for example, whereas MSAA 4x should normally delete the aliasing effect. According to Digital Foundry, this time Turn10 would use a different anti-aliasing technique that would be much less resource intensive.

4K, yes, but not everywhere

The second detail that analysts have been able to discover in Maple Valley’s gameplay relates to the resolution of the game. Again, it seems that Turn10 has moved away from what we have been used to until now, namely a built-in 4K resolution across the entire stage.

In the intro scene to the gameplay presentation, we can see the beautiful Maple Valley circuit with a river following the course. But if we zoom in a bit, we see that the stones are not rendered in 4K, but rather in a resolution that would be around 1080p. Other off-field objects also appear to be in the same case.

According to Digital Foundry, we could be in the presence of an image reconstruction technique or a technology such as Variable Rate Shading. This aims to control the quality of shaders differently depending on the objects displayed in a scene, making it possible to optimize resources and less require the machine’s GPU (graphics processor).

Ray Tracing studied under the magnifying glass

Digital Foundry adds that although Turn10 delivers an image with objects that are not necessarily all in 4K, Ray Tracing remains very resource intensive. How does Turn10 manage to deliver reflections in Ray Tracing? Again, the answer lies in the details.

There are several ways to handle reflections in Ray Tracing in video games, and the least demanding is to use a technique close to the mirror. And it’s the one that seems to have been used in Forza Motorsport, as shown in an excerpt from the trailer presented, where part of the wheel seems to reflect the environment like a mirror, whereas one might expect a softer rendering in reality .

But other passages presented by Turn10, and especially in the game trailer (and not the gameplay), present the same surface with a softer reflection. This is also the case on the engine surface of one of the cars on display in the pit, where the reflectors are much more realistic. By comparing similar scenes between the gameplay video and the trailer, we see that Ray Tracing does not appear to have been applied identically to the same objects. Digital Foundry finally believes that the one-minute trailer does not offer the same Ray Tracing as the 5-minute gameplay.

Gameplay on the left, replay trailer on the right

Will Forza Motorsport offer different levels of Ray Tracing in its PC settings? It’s hard to say right now, but the immediate answer may lie in how the scenes were captured and presented to the audience.

On one hand, we have the 5 minute gameplay video that features Ray Tracing highlights. On the other hand, we have the game’s trailer of about one minute, which is based on replay phases, which benefit from the Global Illumination technique in addition to Ray Tracing. The rendering of the game during repetitions is therefore more realistic than when playing it, which is consistent with the comparison here.

If the game trailer is not from gameplay, but rather from replay stages, why does Turn10 show the mention “All 4K footage in the game” on the trailer video? The developer seems to have taken a shortcut here by judging that the renderings of the game were “in-game”, as the gameplay phases from the second video really are, and yet include a less advanced Ray Tracing and without Global Illumination .

At the moment, the rendering of this new Forza Motorsport in any case works much better than that of Forza Motorsport 7. But to offer Ray Tracing in 4K and 60 frames per second on a console sold for only € 500, Turn10 obviously had to find tricks to relieve the machine’s graphics processor. We will definitely have the opportunity to talk about it again before the game is released. Remember that the developers still have a short year to optimize the game and that adjustments will definitely be made before then.

Forza Motorsport is scheduled for release in the spring of 2023 on the Xbox Series X | S and PC as well as the Xbox Game Pass and PC Game Pass.

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