LucasArts 30>60FPS Tech Demo

[Geble]

Na nedavnom SIGGRAPH-u programer LucasArts-a Dimitri Andrejev je demonstirao zanimljiv tech demo. U video demosntraciji je prikazao kako se od 30 fps moze dobiti 60 frejmova u sekundi bez vidljivijeg uticaja na sam izgled igre, osim uklanjanja motion blur-a.
Samu ideju je dobio od 120Hz televizora koji koriste tehniku dupliranja frejmova. U odnosu na tehniku gde se za 30 fps koristi motion blur ova tehnika manje zahtena za sistemske resurse.

Video demonstraciju mozete skinuti ovde

Ceo clanak

Andreev and his colleagues have devised a system that gives an uncanny illusion of true 60FPS, and uses less system resources than its existing motion blur code. Swap out the blur for the frame-rate upscaler and you effectively have all the visual advantages of 60FPS for "free", as there's very little need to run full-on multi-sample motion blur if your game is already running at 60FP

One solution for making a solid 30FPS title smoother is to use motion blur, and there have been some pretty decent implementations that make the image seem much more realistic and more fluid. Motion blur requires the generation of a so-called velocity buffer, which defines the movement. However, rather than using it for creation of the motion blur, the buffer is repurposed to produce an interpolated, intermediate image that is drawn at the mid-point between two frames.

You'd think that this technique would cause lag, but as the interpolated image is being generated using elements from the next "real" frame, it actually reduces latency. Andreev's technique is single-frame based rather than dual-frame. The latter approach would require buffering two images so has a big memory and latency overhead, while the technique Andreev used effectively interpolates on the fly using past and future rendering elements.

However, the available demo looks pretty astonishing for a proof of concept, and according to Andreev, the bump from 30FPS to an interpolated 60FPS is indeed "free" in that the removed motion blur code is more "expensive", taking up more system resources, than his frame-rate upscaler.

According to his figures, The Force Unleashed II's motion blur eats up 2.2ms of resources on Xbox 360 (give or take 0.4ms), while the five-SPU-powered PS3 version is much faster at 1.4ms (give or take 0.5ms). Compare this with the frame-rate upscaler, which runs at 1.5ms on 360, and 1.4ms on PS3 (again parallelised over five SPUs).

 

[Dodatak]

Fino deluje, jedino sto postoji mali artifkat oko samog karaktera ako se bas zagleda. U svakom slucaju bih pre izabrao ovu konverziju nego motion blur koji je retko kad implamentiran kako treba u danasnjim igrama na konzolama. Usput veliki plus sto jede manje resursa nego kod za motion blur.

 

[DieH@rd]

Shteta sto ce ceo taj tim najverovatnije dobiti kolektivan otkaz kada zavrshe rad na SWTFU2.

 

[Geble]

Izasao je i intervju sa Andrejevim.

http://www.eurogamer.net/articles/digitalfoundry-frame-rate-upscaler-tech-interview

Digital Foundry: Can you give us a basic outline of your technique in layman's terms? Are we really seeing an effective 60FPS with all the advantages of rendering at 30FPS?

Dmitry Andreev: The basic idea is to build an extra frame based of the previous one [using] new information available for the current, new frame, and present it in the middle of 30FPS rendering while still working on the current frame. This way, technically, we are seeing an effective 60FPS with all the advantages of rendering at 30FPS.

Digital Foundry: Can you talk about the process in which you remove the characters from the scene? Why is this necessary? Is it about reducing the artefacting in the interpolation process on the characters?

Dmitry Andreev: This is not necessary in general. As I discussed in comments, all the characters could be re-rendered at 60FPS, or could be rendered separately from the environment. It happens that they can move any way they want. So the easiest way is to have a version of the environment without the characters, and you use that version whenever we detect an artefact.

Now, with forward rendering it is easy to render the environment first, store it somewhere and then render characters on top of it. But it becomes very difficult to do the same thing with the use of deferred techniques. So when I was working on a console implementation I didn't want even to think about redoing most of our deferred rendering pipeline. It is already crazily optimised with different sorts of tricks. That's why I thought it would be easier to just somehow remove them from the existing frame and then use that to remove the artifacts.

Digital Foundry: The presentation has stirred up a lot of interest from members of the development community we've talked to. Can you think of any situations where the technique could be deployed now? Who do you think would be first to market with a game based on this idea?

Dmitry Andreev: Well, I think that for EA running at 60FPS is very important, especially for EA Sports. And I think that most of those sport games are a lot easier to make work with this technique as some of their engines are based on forward rendering. So I would try to render the environment like stadiums and tracks at 30FPS with all the characters running at a real 60FPS.

In terms of "when", I think that games already running at 60 will stick to a real 60FPS and titles that are in production and running at 30FPS will most likely to keep it that way. But the ones that are in pre-production or early in production may try this out, which might take at least a year. I will not be surprised if it will be EA using this sometime soon, but the real utilisation might come from more tech-oriented companies like Naughty Dog. We will see.

 

[padawan]

Kul, FIFA ce konacno liciti na nesto posto imam utisak da je framerate padao i ispod 30.

 

[Dodatak]

Ovo bi bas znacilo u sportskim igrama, bilo bi lepo da neko nastavi sa ovim ako vec LucasArts nece.