Video game industry veteran and HDR and color grading specialist at Gamma Studios, Filippo Tarpini, believes that Rockstar Games might be using a cheaper SDR upgrade rather than true high-quality HDR in Grand Theft Auto 6. In a series of social media posts, Tarpini has analyzed a variety of scenes from the title’s most recent trailer and has brought up a few problems with the studio’s implementation of HDR.
“The launch trailer is SDR but still gives us insight into how they are working with colors. Overall, what I see looks nice. Nothing appears particularly broken with one big exception. Gradients are smooth. Skin tones are great. Hue paths/shifts are ok. There’s a lot of clipping, but that’s unavoidable in SDR. However… as often happens: bright blue turns purple!”
Pointing to the swimming pool scene from the launch trailer, where lights that should ideally turn the blue pool water into a lighter shade of blue, the points where the lights are the brightest instead show the pool water being purple. “This is a typical trait of tonemapping per channel; Unreal/ACES have a ‘blue correction’ feature to remedy this problem, which introduces issues like banding.”
This has led Tarpini to believe that Rockstar Games is using a per-channel implementation dubbed AgX. “It usually doesn’t escape this problem, in fact, it can even make it worse given it has no gamut adaptation.” After pointing out a few more examples of colors showing incorrectly due to high brightness from specific elements, Tarpini goes on to discuss why Rockstar would choose to use AgX over other methods.
Interestingly, Tarpini has also noted that AgX doesn’t have an official HDR implementation, and “nobody in the industry seems to be able to adapt its math to HDR.” Citing further analysis by game modder MusaRenoDX, Tarpini believes that the company is using inverse tonemapping techniques for its HDR implementation without adding extra details for the highlights.
“That does not bode well! The biggest game in the world using a cheap SDR-to-HDR upgrade method would be a real shame, but we have come to expect the worst when it comes to HDR. Hopefully I’ll be positively surprised.” In a bonus post, Tarpini praised the look of explosions in the launch trailer, noting that they are “clearly tuned to look great in SDR too.”
The launch trailer, released earlier this week, gave us glimpses of the story in Grand Theft Auto 6, and in the process, also provided some hints about Jason’s backstory and how he and Lucia come together to get involved in a life of crime. There are also mentions of Jason’s departure from the Army not being “on the best of terms”, and an “easy score” that has seemingly gone wrong, leading to questions about whether the two of them will be “okay”.
Grand Theft Auto 6 is making its way to PS5 and Xbox Series X/S on November 19th. For more details about the title, check out the lengths that Rockstar went to in order to have appropriate NPC chatter in the open world. And for more on the launch trailer, take a look at our analysis.
