ACES is a standardized color management system widely used in the film and visual effects industry to ensure consistent and accurate color reproduction throughout the production pipeline. Integrating ACES into game engines like Unreal Engine could have significant benefits, especially for game developers who want to achieve high-quality, consistent color representation across different platforms and displays. Game developers can achieve heightened visual fidelity by leveraging ACES in Unreal Engine 5, especially concerning wide color gamuts and high dynamic range (HDR) content. The standardized color management system allows cross-platform development, guaranteeing consistent color reproduction on various devices and display technologies. Moreover, Unreal Engine 5's support for ACES facilitates seamless collaboration with other creative industries that utilize this industry-standard color pipeline. However, implementing ACES in a real-time engine presents unique challenges regarding performance optimization and ensuring compatibility with other game engines. Artists and developers may need to adapt their workflows to accommodate ACES color transforms, impacting the art pipeline and user-generated content. This paper uses ACES to investigate color input and output consistency to and from Epic Games Unreal 5 regarding Wide Color Gamut and High Dynamic Range imagery.
In modern moving image production pipelines, it is unavoidable to move the footage through different color spaces. Unfortunately, these color spaces exhibit color gamuts of various sizes. The most common problem is converting the cameras’ widegamut color spaces to the smaller gamuts of the display devices (cinema projector, broadcast monitor, computer display). So it is necessary to scale down the scene-referred footage to the gamut of the display using tone mapping functions [34].In a cinema production pipeline, ACES is widely used as the predominant color system. The all-color compassing ACES AP0 primaries are defined inside the system in a general way. However, when implementing visual effects and performing a color grade, the more usable ACES AP1 primaries are in use. When recording highly saturated bright colors, color values are often outside the target color space. This results in negative color values, which are hard to address inside a color pipeline. "Users of ACES are experiencing problems with clipping of colors and the resulting artifacts (loss of texture, intensification of color fringes). This clipping occurs at two stages in the pipeline: <list list-type="simple"> <list-item>- Conversion from camera raw RGB or from the manufacturer’s encoding space into ACES AP0</list-item> <list-item>- Conversion from ACES AP0 into the working color space ACES AP1" [1]</list-item> </list>The ACES community established a Gamut Mapping Virtual Working Group (VWG) to address these problems. The group’s scope is to propose a suitable gamut mapping/compression algorithm. This algorithm should perform well with wide-gamut, high dynamic range, scene-referred content. Furthermore, it should also be robust and invertible. This paper tests the behavior of the published GamutCompressor when applied to in- and out-ofgamut imagery and provides suggestions for application implementation. The tests are executed in The Foundry’s Nuke [2].