How Square Enix impressively optimized FINAL FANTASY VII REMAKE INTERGRADE for next-gen

Not only have loading screens been minimized, but textures load much faster, too, which is especially evident in the Sector 7 slum area of the game. Can you talk about the work that went into improving those streaming issues using Unreal Engine?

Hano: In the PlayStation 4 version, we had to forgo using a higher-quality format and high-resolution textures due to memory and disc capacity restrictions. However, we still didn’t have enough disc capacity with FINAL FANTASY VII REMAKE INTERGRADE to include a high-quality format and high-resolution textures.

And so, we integrated Oodle Texture [Compression], and by using it in combination with Oodle Kraken, we were able to achieve a smaller file size on the PS5 version, even taking the higher resolution textures into account. 

Plus, the increased memory compared to PS4 and the improvement of the Non Streamable Mip Map, which ties into the response of the aforementioned question, also helped to load textures.

We were also able to use more high-resolution light maps, which improved the accuracy of the lighting. 

Not only is the lighting improved, but Digital Foundry pointed out that new light points were also added to FINAL FANTASY VII REMAKE INTERGRADE. Can you elaborate as to why these were included?

Ikeda: Since we were able to leverage more wiggle room with our resources, it did allow us to add more light assets in various locations. The purpose here was to add more information to some of the flat areas, which helps emphasize the hustle and bustle of Midgar. 

FINAL FANTASY VII REMAKE INTERGRADE features upgraded screen-space reflections (SSR), which are really noticeable on water reflections. Can you talk about the work that went into this enhancement?

Ikeda: The SSR we used in FINAL FANTASY VII REMAKE INTERGRADE traces rays not just from glossy surfaces, but also rough surfaces, which generally tend to be omitted. By doing so, a more accurate occlusion is considered geometry-wise, and so you can see things like the light of a foot lamp bouncing off of a surface, or the hilt of Cloud’s sword being reflected in its guard.

There were times when aliasing from ambient light passing through could be seen on the eyes and the nose, which was a bit unsightly, but that was dramatically reduced. Typically, the mapping vectors obtained via normal mapping point in directions that would not be visible by the line of sight in many instances. When using these vectors in SSR, the direction of the reflection points to the inside of the surface, so it will always return a tracing error. This time, the mapping vectors on the polygon surface were stored in the buffer as well, and we corrected the error pixels when reflections were created to combat this issue.

In typical SSR, the image in the previous frame would be referenced, so whenever something like a camera switch happens, you can see a delay in the reflections being processed. For this title, whenever something like that happens, we would prioritize rendering the incomplete current frame so it would make an alternative reference, in order to address any hopping. Additionally, in a typical implementation, the prior frame that is referenced may already have the fog rendered, which causes that fog to be processed twice when referenced in SSR.

While we were developing the imagery, we would get a very strong impression of the volume fog, with this error being exacerbated on water surfaces that reflected the distant landscape. So, we stored two images–with fog and without–so that the fog density can be more environmentally appropriate when reconstructed based on the distance reached by the reflection ray, thus achieving a much more natural reflection. 

FINAL FANTASY VII REMAKE INTERGRADE employs volumetric fog, which can change the mood of environments like the gardens outside Aerith's house. Can you elaborate on why this implementation was a good fit for the next-gen update and explain how you implemented it using Unreal Engine?

Ikeda: We had already been using volumetric fog, but their settings as assets, such as positioning and density, were not optimal. So, we chose to remove all arbitrary parameters and tried to stick to PBR (physically based rendering) so that we can fill Midgar with a more consistent atmosphere.

Fog density and such are painted into the space of the world like a brush by the artists. This is then laid into the space as probe data, and then injected into the calculation voxel inside the viewing frustum of the camera in runtime. This takes heat haze into consideration as well, so if you look closely, you may notice that the light shafts are slightly waving.

Sources that shine on the fog consist of not only punctual light sources, but the multiple light probes that fill the space as well. The calculation model for scattering was conformed to Mie scattering, and front-lit was also shown without omission. This fog can be injected from effects as well–a good example of this can be seen in Nero’s attacks. 

On top of all the visual enhancements, FINAL FANTASY VII REMAKE INTERGRADE does a great job maintaining a consistent 30 frames-per-second at 4K in graphics mode or 60 frames-per-second at a lower resolution in performance mode. Can you talk about the work that went into optimizing the game to hit those performance targets?

Hano: One of the efforts from the PS4 version that helped us was the workflow we established so we can improve the load we place on processing. First, we looked at what was imperative to revise, and determined the processing load regulations. Based on that, the QA team would check areas that do not follow those regulations and report them to us via a bug report. That report is then handed off to the optimization programmer. The profiling results, issues, and solutions are sent to each person responsible for handling the work. We would repeat the process until items were well contained within the scope of the regulation. Through these efforts, we were able to get an understanding of many of the issues through the player’s perspective and achieve a stable framerate.