LotF Dev: DX12 Isn’t A Magic Wand; Great Improvements From Async Compute
Here’s another excerpt of our massive interview with Michele Giacalone, Engine/Graphics Programmer from Deck13 Interactive (working alongside CI Games on Lords of the Fallen, the promising action RPG title scheduled for release in a couple weeks). We asked him his opinion on such hot tech topics as DX12 (and more generally the trend towards lower level APIs on PC, including Mantle, which he believes to be limited by its AMD-only application) and Async Compute; on the former, he said that while DX12 will indeed grant better performance on PC, it shouldn’t be seen like a magic wand.
I will be honest here, I think Mantle or low level API in general are quite complex concepts to grasp, especially without a technical background. A low level API is basically some kind of simple set of functionality that maps closely to the hardware allowing developers to unlock extra performance that wouldn’t be possible using high level API such as DirectX 11. This comes in cost of extra effort from the developers because they have to take into account more things that are not handled automatically anymore. This is what you usually do on consoles, so this isn’t a new concept at all, it just has gained audience after Mantle went public. Honestly I won’t bet on Mantle right now, mainly due to its platform restrictions, but on the other hand I really appreciate the direction they have marked for the future of graphics API for PC platforms. DirectX 12 will be surely a way to achieve better performance on PC platforms, but don’t see it like a magic wand, it will take time and a lot of efforts before developers can squeeze the maximum power out of it.
On the latter topic, he pointed out that Async Compute can be exploited on PC as well via Mantle, and that he expects great improvements by going in this direction.
Asynchronous Compute is not a new console bound technology, titles using Mantle can take advantage of the powerful AMD GCN architecture as well, and this is surely one of the most interesting aspects to dig into. Our engine supports heavy compute based features, such as particles, hair and grass simulation. We didn’t manage to use them for this project due to time constraints but those are a great starting point for us to experiment with async computes. We also started to redesign our render process to completely hide the cost of some expensive passes. I am expecting great improvements going in this direction.
This seems to be something that many developers agree with. Just a couple of days ago we have published the report of a Ubisoft test on moving cloth simulation to GPU while developing for PlayStation 4 & Xbox One, and before Michele there have been other developers speaking on the matter, from Sucker Punch to Zombie Studios; perhaps one of the first games which is heavily using Async Compute is The Tomorrow Children, a PlayStation 4 exclusive by Q-Games.
Come back on Monday for our full interview with Michele Giacalone.