Final Fantasy XIII: How Will It Work on 360?

The way we see it, there’s both good news and bad news for owners of the Microsoft console. The good news is that from a purely technical perspective, looking at the game engine as it stands in the demo, there is literally nothing there that couldn’t be achieved on the Xbox 360, with perhaps one exception that we’ll get to later. To tell the truth, we’re not looking at an exceptionally advanced engine here – this is no Uncharted or Killzone. Instead, it’s all about the quality of the art assets, and we see nothing here to suggest that those assets won’t be identical on the Xbox 360 version.

In fact, the main cause of the frame drops in the PS3 demo (which Square has pledged to fix) shouldn’t cause many problems for the 360 at all. Square has clearly had issues handling transparent alpha textures – it’s the single biggest contributor to frame loss in the demo. And it’s the reason there’s a bizarre dithering around the characters’ hair. Due to the 10Mb of onboard eDRAM directly connected to the Xenos GPU, alpha blending has far less of an impact on performance with the 360. In some scenes we expect the 360 version to have the edge over the 'native' PS3 code.

While the eDRAM gives the 360 tangible advantages over the PS3 (it’s the reason why so many cross-format titles have anti-aliasing on 360 while it is omitted on the PS3 versions), 10Mb isn’t really enough for a full 720p framebuffer with the added overhead of anti-aliasing. Instead, developers switch memory in and out of the eDRAM in a process called ‘tiling’. This incurs an increased geometry cost for polygons that span more than one tile. In plain English? Realistically we expect the 360 version to match the 720p and 2x multisampling anti-aliasing of the PS3 game, but at a cost – the HDR lighting in the PS3 game will most likely be pared down from high range to medium range dynamic rendering.

Few games on 360 run with ‘proper’ HDR. Halo 3 is one of them, but this comes at a cost of a sub-HD resolution and no anti-aliasing. In the case of Final Fantasy XIII, the drop down to MDR simply makes more sense as opposed to savagely cutting down resolution or anti-aliasing. So aside from small changes to lighting, we expect the games to be totally like for like in the real time 3D sections, and due to that lightning fast eDRAM, there’s a strong chance that performance may actually be smoother. How small will the changes to lighting be? Considering we spent the best part of the day firing off 'is it proper HDR/isn’t it' emails to one-another, let’s just say that it’s highly unlikely any one will notice. A useful by-product of moving away from proper HDR on 360 will be that the alpha transparency issues the PS3 version has with the way it handles characters’ hair will most likely vanish.

As it happens, 3D performance is the least of our concerns. The one thing that surprised us about the demo more than anything else was its incredible reliance on streaming HD video from the optical disc. Even in a demo you can finish in 30 minutes, there’s a ton of it. Assuming the final PS3 game is on a single layer 25GB BD, conceivably the game would work as is across four DVDs on 360. But all bets are off should the game migrate onto a dual layer 50GB BD as has been suggested.

Lower quality video is of course an option, but the real question has to be why the FFXIII team is using video at all for most of this stuff. There’s really nothing here that couldn’t be done in real-time. The pre-rendered sequences are more effects heavy than in-game, with higher levels of detail, but Resident Evil 5 is a supreme example of how the carefully stage-managed cut-scenes allow for more expansive LODs and more ambitious effects – exactly what’s going on here. Our guess? Such scenes will indeed be real-time on Xbox 360, saving gigabytes of data over the PS3 version with only minimal amounts of difference in the quality of the visuals. Streaming in new game assets may well require additional loading time, however. Of course, it may well be the case that these videos are only there to supplement an incomplete engine, and that they will be replaced with real-time engine-generated scenes in the final PS3 game too. However, our bet is that Square-Enix will make use of the storage on offer and keep them as excellent quality video sequences.

The official line from Square-Enix is that work on the Xbox 360 game will only begin when the Japanese PS3 version of the game is complete later in the year. Our gut feeling is that this is not the case. While work on converting FFXIII itself may not be happening now, porting Crystal Tools engine that powers the game is another matter entirely (indeed, certain reports online confirm our thinking). If the core engine that runs FFXIII is being coded on 360 as we speak, as we suspect it is, you can bet that the team already have the methodology in place to convert the game, and will be addressing exactly the issues we’ve covered here.