Chris McCue, Technical Director of World of Tanks gives us the lowdown on PS4 Pro and Xbox One X implementation.
World of Tanks currently supports the PlayStation 4 Pro and it will also support the Xbox One X when Microsoft launches its newest console next month. In order to know more about the technicalities behind each version, we got in touch with Chris McCue, Technical Director of World of Tanks who told us everything we need to know about the latest consoles.
To begin with, can you please tell us about the engine that World of Tanks is running on?
World of Tanks Console uses the Despair client engine, developed internally by Wargaming-Chicago Baltimore, in combination with Wargaming’s BigWorld server technology.
What kind of improvements have you made to the engine in terms of physical based rendering, global illumination and lighting?
Our renderer uses a physically-based model which preserves high dynamic range values throughout the entire pipeline. We were one of the first games to support HDR display output on the PS4, PS4 Pro, and Xbox One S, and of course we will support HDR display output on the Xbox One X (Scorpio) at launch.
"World of Tanks PC is developed independently from World of Tanks Console, so there’s no direct comparison between the two. "
The PS4 Pro version runs the game at 3200 x 1800 resolution. What kind of challenges you went through to achieve this?
We discussed the PS4 Pro extensively with Sony before and during our development effort so that we could maximize the performance of the game on the new hardware. It was important to us not just to use the raw additional power of the PS4 Pro, but also to understand and take advantage of new features which could affect performance in very specific ways. We constantly update our game with new content, so the biggest ongoing challenge is maximizing visual quality and performance on both the PS4 and the PS4 Pro with minimal disruption to our artists’ workflow.
Along with a boost to resolution, what other improvements were implemented in the PS4 Pro version?
Although the primary visual improvement for the PS4 Pro was the resolution increase, we made additional changes to improve shadow quality, ambient occlusion, and level of detail. In addition, for those players who have a PS4 Pro without a 4K television, we use the extra GPU power to improve our antialiasing at 1080p.
World of Tanks PC is developed independently from World of Tanks Console, so there’s no direct comparison between the two. When comparing the PS4 Pro version to the base PS4, though, we’ve kept the differences strictly to the visual improvements described above because it’s important to us to maintain a consistent user experience. There are no new features that only exist on the PS4 Pro.
Mark Cerny, the lead engineer of the PlayStation 4 Pro claims that converting a base PS4 game to PS4 Pro version is just 0.2 Or 0.3% of the overall effort. Your thoughts on this?
It’s nearly impossible to measure some piece of work as a percentage of the overall effort of developing an entire game, so I don’t think we can speak to the accuracy of those numbers. The level of effort required was what we would consider reasonable for a new hardware platform, though.
"The increase in power from the base Xbox One to the Xbox One X is a close match for what is required to bring a 1080p game up to 4K, so without significant additional renderer changes it’s not enough to also increase framerate from 30 fps to 60 fps."
Please share your thoughts on the advanced work distributor in PS4 Pro along with new Polaris features like Delta color compression.
Work distribution on the GPU generally happens automatically, so we see better work distribution just as improved GPU performance without requiring any manual effort. Delta color compression is different because we do have to choose when to use it. It benefits certain portions of the game rendering more than others, making it a useful optimization but not a game changer in terms of overall GPU performance.
Furthermore, the PS4 Pro’s capability run multiple wave fronts on the GPU compute units…has this benefitted development in any way?
Our renderer uses compute shaders extensively, so improvements to compute hardware provide a broad performance benefit for us.
In a recent Reddit AMA, the development team claimed you could potentially run the game at native 4K on the Xbox One X . I find that comment interesting because the Xbox One X has been designed as a native 4K console to begin with. But do you think it’s capable to run the game not only in 4K but at Ultra PC settings and that too at 60fps?
The increase in power from the base Xbox One to the Xbox One X is a close match for what is required to bring a 1080p game up to 4K, so without significant additional renderer changes it’s not enough to also increase framerate from 30 fps to 60 fps.
As for graphics settings, because we’re a console title we don’t have user-configurable “Ultra” settings but our artists work hard to ensure the game looks amazing on all of our supported consoles.
What kind of advantages does the PS4 Pro’s 2X16 bit operations have over the Xbox One X?
World of Tanks Console is at 30 frames per second on all consoles, including the PS4 Pro. We’ve found that the ability of the PS4 Pro shader hardware to perform two simultaneous 16-bit operations is, like the earlier answer about delta color compression, a feature which is very useful for some parts of rendering but does not by itself result in significant framerate increases.
"We’ve actually found the CPU and GPU improvements to complement each other quite well. Increasing the resolution from 1080p to 4K uses much of the additional power of the GPU but has basically no effect on the CPU."
Xbox One X has a ton of memory on board (12GB in total and 9GB of that is available for games). Do you think high-end PC game developers such as yourself, will now be setting your PC memory requirements even higher in the future due to Xbox One X offering even higher memory allocations?
World of Tanks PC is developed independently from World of Tanks Console, so improvements to console hardware won’t have any effect on them. For World of Tanks Console, though, the additional memory on the Xbox One X gives us the ability to render more higher-resolution textures than we’ve ever been able to do before!
The Xbox One X has undergone minor but noticeable improvements on the CPU front but Microsoft’s push for DirectX12 for GPU seems to have done a lot of good for the console’s GPU. But do you think the somewhat mediocre improvement in CPU will hold back the Xbox One X?
We’ve actually found the CPU and GPU improvements to complement each other quite well. Increasing the resolution from 1080p to 4K uses much of the additional power of the GPU but has basically no effect on the CPU. With those extra pixels available to display fine detail, though, we’ve chosen to extend our LOD ranges so that more objects render in the distance. That kind of change has CPU cost that is a good fit for the improved hardware there.