Ubisoft Deep Dives in PS5 PRO – PlayStation.blog updates

Hello everyone! We have just published the update of title 1.0.2 which added some key improvements to the PS5 pro version of Assassin's Creed ShadowsIncluding the addition of PSSR support and the inclusion of reflections drawn by radius for balanced mode.

To celebrate, we wanted to give you a more in -depth overview of the work done to bring this version – the best version of the Shadows console – to life.

Make our vision of rendering

As players, we are always delighted to see new equipment. As developers, we are even more excited and the PS5 Pro is no exception. As soon as we have been informed of the new console capacities, we were delighted to take advantage of it; The PS5 PRO allowed us to push our vision of rendering to its full potential in all modes – quality, balanced and performance.

First of all, let's summarize the three basic technological improvements. The PS5 PRO has three compared to a standard PS5:

1. He has a faster GPU.
2. It has new spoke tracing capacities (BVH8 support).
3. It has a super spectral resolution PlayStation.

Take advantage of the GPU tracing capacities and improved rays

At the start of the AC shadow design phase, we decided to revolutionize our lighting pipeline by passing from a precoed world lighting¹ System with limited flexibility in the game to a runtime, Ray traced, a. There are several advantages of image quality to this, and this allows much more dynamism in the world, because lighting can always adapt to what is happening in the game. The quality is also increased and subtle, but important lighting details, emerge when using global lighting traced (RTGI). Although the PS5 has allowed us to target 30 and 40 IPS in a realistic way with its native ray traced support, it did not fully allow 60 IPS, taking into account everything that happens on the GPU: simulations, raterization and shade of geometry, deformation of character and rendered for hair, etc.

However, with the announcement of the PS5 PRO last year, we knew that we had all the ingredients to build the ultimate console version of AC Shadows. In itself, the faster GPU of the PS5 PRO helps performance without too much effort from developers, but the technology that changes the game is the tracing capacities of the improved rays of the PS5 Pro that BVH8² (BVH means “Bounding Volume Hierarchy”, more below) offered on BVH4. With our implementation of the BVH8 support on PS5 PRO, we were able to speed up GPU tasks involving the use of the material tracing of around 300%. These 2 critical upgrades, the GPU and the faster management of BVH8 allowed us to realistically target 60 stable IPS while presenting our lighting engine drawn from new generation rays.

1. What is global lighting?

In the rendering of the game, Global Illumination (GI) refers to a set of techniques used to simulate the way in which light interacts with surfaces in a 3D environment. Rather than illuminating objects with a direct light of a light source (like the sun or a lamp), GI explains indirect lighting, which is a light that bounces on surfaces and contributes to the overall lighting of a scene.

Think of the following scenario: if you place a red box near a white wall in a well lit room, the red color “bleeding” on the neighboring wall.

2. What is a BVH?

A BVH, or hierarchy of delimited volume, is an acceleration structure which is at the heart of the use of the layout of the material rays in 3D graphs. Consider it like boxes in boxes. If you have to trace a radius, determine the large boxes that first cut the department, then test recursively is what makes tracing of the rays possible with the performance corresponding to the requirements of modern games.

As a rule, BVH has 4 large boxes (BVH4), which means that each box can contain 4 other boxes. With BVH8, we have 8 boxes per box, which allows a faster crossing of the BVH when performing GPU tasks to trace rays than the tree is less deep, each node having twice as many children.

Something unique to console players on PS5 PRO: Ray Traced reflections

Ray draws global illumination to 60 IPS in an open world is a great feat alone. However, given the delay in AC shadows, we had time to assess how we could push things further, and we have become convinced that we could implement reflections drawn by rays¹ in time for the launch.

The use of tracing reflections for rays solves many problems encountered with conventional techniques such as SSLR and Cube Maps. While some PS5 Pro Games had opted for a single 60 IPS mode, our approach was: if a choice between playing at 30, 40 and 60 IPS was good for PS5 players, why not reproduce this for PS5 Pro players, if significant improvements could be offered in each mode?

With the reflections drawn by radius, we think that an important uprising in the photorealistic rendering is obtained. Again, this was possible because of the faster GPU as well as the acceleration of 300% in the tracing capacities of the rays that we were able to make by taking advantage of BVH8.

At the launch, we offered reflections traced with rays only during reading in quality mode, but we are pleased to announce that the update of title 1.0.2 brings reflections drawn by Ray in balanced PS5 Pro mode, an improvement that many of you have requested. Again, the balanced mode offers an excellent compromise between quality and performance, for players with support TVs.

In short, PS5 PRO brings:

• Ray has drawn the global illumination in performance mode (compared to the pre-cooked overall lighting on the standard PS5.)
• The reflections drawn by radius in quality and balanced mode (complementary with the global lighting drawn of the rays present on the standard PS5.)

What are the reflections?

Reflections refer to the way in which light is reflected on shiny, metallic surfaces, etc. While reflections are mainly noticed on these types of surfaces, they affect most of the pixels on the screen in a very subtle manner which founds the image. Usually, this is done using information on the screen, with a technique called Screen Space Reflections Local Reflections (SSLR) or using older techniques such as cubes cards, which are offline or dynamically rendered with a lot of latency and lower resolution, due to memory and storage constraints. The reflection drawn by radius solves the main problem with SSLR is that it cannot reflect what is outside the screen and has a much higher level of fidelity than cubic cards.

Support the PSSR

With everything we have discussed so far, we have only covered two of the three key improvements that the PS5 Pro provides. What remains is a piece of PS5 PRO technology called PlayStation Spectral Super Resolution, alias PSSR. First of all, let's explain what the PSSR is. The PSSR is a high level focused on AI, which means that it takes an image rendered to a lower resolution, let's say 1080p and increases them up to 2160p, approximating 3 pixels out of 4 in other words (the scale is nothing new; the decline in the resolution of the rendering leads to a higher category. The compromise is that of the clarity of the image, and sometimes the visual artefacts. Analytical, which means that it is based on mathematics and statistics, in general.

The scaling combined with a dynamic resolution scaling (DRS), a technique where the rendering resolution changes according to the way in which the GPU has carried out in AI, allows us to maximize the visual fidelity of the game by lowering the resolution pre-to scale in more demanding scenarios. Without DRS, we would need to calibrate our budgets for the worst scenario, even if they only occur in specific circumstances and once in the whole game. Consequently, good DRS implementation associated with a high high level offers the best of both worlds: a higher category and a more visual loyalty.

AI speakers are generally formed with reference images in target resolution. Unlike a high analytical level, they can work better with lower pre-deplery resolutions, because their code of difficult behavior code, although impossible, to reproduce analytically. With the delay in AC shadows, we had precious opportunities to explore the first implementations of the PSSR in other improved PS5 Pro titles and to carry out our own in -depth analysis on AC shadows. We found that the PSSR offered a higher experience compared to TAA overall, and was certainly something that could benefit the players. Recognizing this, we contacted Sony Interactive Entertainment (SIE) for additional collaboration. Sony has worked in close collaboration with us, providing updated model parameters to perfect our implementation in the last PS5 Pro firmware, which has just been published. Compared to TAA, the PSSR brings a more stable image with artifacts in particular less shimmering, which reveals the quality of the image.

This firmware being now released, we are pleased to say that the official PSSR support is now available in AC Shadows thanks to our new title update, because the improvements made to the system software and our work in the engine will now work transparent together. Players who have already played the game on PS5 PRO will have to activate the option in the Video tab of the Options menu, but all new players will play by default with PSSR Activated. As always, we are committed to improving our implementation in updates to the upcoming title while this technology continues to evolve.

Conclusion

With global lighting drawn in performance mode (60 IPS), the reflections drawn by radius coming in balanced mode (40 IPS mode) as well as in quality mode (30 IPS) and PSSR now available in all modes, we are very satisfied with our PS5 PRO version and believe that it is the experience of the ultimate AC console for AC Shadows, which rivals PS5 PS5 PC. We have fully exploited the 3 basic technological pillars of the PS5 PRO, and combined, they really support our technological vision and have really excited us for the future!

We hope you appreciated this deep technical dive in the creation of the PS5 Pro version of Assassin's Creed.

Thank you Nicolas Lopez, Technical Architect and Sébastien Daigneault, main programmer of the project – rendered for helping to contribute to this article..