Forza Motorsport in 4K / 60 FPS / Ray Tracing: the 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 reaching this level on PC would require war machines? Digital Foundry delved into the matter and analyzed the trailers released by the developers, highlighting some very interesting details.

Anti-aliasing other than MSAA x4?

The first technical information regarding Forza Motorsport rendering is impressive as very few games manage to reach that level. The developers have about a year left to make the optimizations, but the technical specialists at Digital Foundry have discovered the tricks that allow Turn10 to get the rendering they claim.

On Xbox Series X, the game will be available in 4K and 60 FPS with Ray Tracing Reflections enabled during gameplay. The gameplay shown at the Xbox conference was running on PC, but Turn10 later made it clear that the demo was also tested on Xbox Series X for a similar rendering. We are therefore waiting to see this version at a later time, but you can watch the videos on your 4K TV while waiting for a preview of the rendering on PC.

Digital Foundry points out that even very high-end PCs have trouble handling reflections in Ray Tracing when a game runs 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 on the native resolution of consoles with MSAA 4x (Multisample anti-aliasing), an anti-aliasing technique that applies sampling only to the edges. But with this new Forza Motorsport the developers have apparently opted for a different strategy, if we are to believe the videos shared by the developers. By slowing down some transmission sequences, we realize that anti-aliasing is not applied to some body elements, for example, while the 4x MSAA should normally cancel the aliasing effect. According to Digital Foundry, Turn10 would this time use another anti-aliasing technique that would require far fewer resources.

4K, yes, but not everywhere

The other detail that analysts were able to detect in Maple Valley’s gameplay concerns the resolution of the game: even in this case, Turn10 seems to have moved away from what we were used to until now, which is a native 4K resolution across the board. the scene .

In the introductory scene of the gameplay presentation, we can see the pretty Maple Valley circuit with a river following the track. But zooming in a bit, we see that the rocks are not rendered in 4K, but rather in a resolution that would be around 1080p. Other objects outside the track 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 manage shadow quality differently depending on the objects displayed in a scene, which allows you to optimize resources and reduce the consumption of the machine’s GPU (graphics processor).

Ray Tracing studied under the magnifying glass

Digital Foundry adds that even though Turn10 provides an image with objects that aren’t necessarily all 4K, ray tracing remains very resource-intensive. How does Turn10 manage to provide reflections in Ray Tracing? Again, the answer lies in the details.

There are several ways to manage reflections in Ray Tracing in video games and the least expensive is to use a technique near the mirror. And that’s what appears to have been used in Forza Motorsport, as an excerpt from the trailer presented shows where part of the wheel appears to reflect the environment like a mirror, when in reality a softer rendering would be expected.

However, other passages presented by Turn10, and in particular in the game trailer (and not the gameplay) present this same surface with a softer reflection. This is also the case with the engine surfaces of one of the cars on display in the pits, where the reflections are much more realistic. 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. Finally, Digital Foundry thinks that the one-minute trailer does not offer the same Ray Tracing as that of the 5-minute game.

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

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

For the moment, the rendering of this new Forza Motorsport still looks 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 for lighten the graphics processor of the machine. We will certainly have the opportunity to talk about it even before the game is released, remember that the developers still have a short year to optimize the game and that some adjustments will certainly be made by then.

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


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