Tuesday, 22 March 2011

Tech Analysis: Homefront (360 vs PS3)

THQ's ambitions as a publisher have been laid out on a plate for all to see. With Homefront they aim to compete on the same level as Activision and EA with their top-tier military shooters - namely Call Of Duty and Battlefield - thus making their own mark within a vastly overcrowded genre. But doing so is no easy task. And in order to achieve their lofty goal they need to deliver something as production-line polished as those titles, but with greater scope and a bigger bang.

Sadly Kaos Studios take on things leaves a lot to be desired. While the multiplayer modes are filled with plentiful options and neat touches which balance out the game for both the hardcore elitist and the casual player, the campaign mode of Homefront feels rough around the edges and tightly pre-scripted, let down by poor design choices and the unwillingness to let the player really take control in driving forward the action. It is rather atmospheric however.

On the other hand, Kaos' use of the Unreal Engine 3 commands at least some respect. The developer has taken a engine which is most suited for smaller, more enclosed spaces and customised it to handle much larger draw distances, and wider expanses of terrain which deliver an added sense of scale to the proceedings. It's not the first time that this has been done: Frontlines: Fuel of War used the engine as a building block for something bigger and better, whilst Epic's own Gears Of War 2 showed how the tech was capable of breaking free from its original constraints.

A fair amount of work has also been put into the multiplatform aspect of the game's development, tayloring certain graphical elements for each console. As a result we see some noticeable plus points for the PS3 over the 360, and vice-versa. However, both games are visually underwhelming, with a range of issues from sub-HD framebuffers to a few poorly implemented effects.

It's fair to say that neither version holds a candle to the very best shooters which utilise the very same engine, though not without some merit.

The game world itself provides much in the way of atmosphere, with the developer's impressive use of lighting, and the building up of a detailed, middle American town scape ravaged by war both helping to connect you with what's going on inside your TV screen. However, that sense of immersion is disrupted by the game's inconsistent visual nature.

The framebuffer for example, comes in at a lowly 1024x576 (basically PAL DVD resolution) on both formats. There's a distinct blur over the entire image which helps hide intricate texture details, along with plenty of noticeable edge shimmering. Pretty much everything looks hideously fuzzy, marred by the hefty upscale that's going on here.

Xbox 360 owners get the benefit of 2xMSAA helping in smoothing over some of the jaggies and reducing a few upscaling artefacts. Whilst on PS3, the game runs without any kind of anti-aliasing whatsoever, thus making it look even rougher as a result. Both are far from delivering anything close to native HD goodness, but its clear that the 360 version features slightly better IQ.

The drop in resolution may come as a shock to some, but in the context of producing a highly detailed and reasonably open landscape, there are significant costs involved - especially when you take into account the game's stellar HDR lighting implementation and real-time shadowing. The additional memory bandwidth and GPU cycles spared by rendering in a sub-HD resolution allow for longer draw distances and considerable more intricate environments. And therein lies the compromise.

Of course, in upping the amount of rendering you have to do for any given scene, this often means carefully implementing LOD set-up and object/texture steaming in order to maintain a high level of detail without impacting on the core graphical make-up of the game. Older titles that used the UE3 featured prominent texture streaming issues, whereby higher resolution textures would pop-in extremely close to the player. Although since then, this has become far less of an issue, with changes in the way transitions between textures are displayed.

In Homefront we see that these refinements aren't present at all, and the end result is that both versions feature some noticeable texture pop whist the engine loads in the higher quality assets. You can see this in the screenshots above. But in this case it is the PS3 game which suffers far less from these issues - sometimes higher quality assets never load in on the 360 either.

We can almost certainly say that this is a direct result from the game imposing a mandatory install onto the system's hard drive, thus allowing content to be streamed in much faster than directly of off the DVD on 360.

On the flip side we find that most of the game's art assets are basically identical, with only a few instances of less detailed textures gracing the 360 version (sometimes it appears that higher resolution assets never load in). Use of texture filtering on 360 also appears to be better too, with higher levels of AF (anisotropic filtering) being present. Although, this does very little to improve the look of the game.

Moving on, there are a few other differences between the two games.
Starting with the foliage, and we can see above that certain plants and bushes are being rendered in a lower resolution in the PS3 game, whilst others are completely missing from the scene altogether. As only a few small objects have been cut back on, it's often hard to see any difference, which thankfully means that it has little to no impact on the look of the PS3 game in any meaningful way.

Secondly, there is the use of lower resolution alpha buffers on both formats. Effects have been filtered accordingly to look smooth, but some - like fire in particular - look very flat and unconvincing. Smoke other the other hand, has a reasonable amount of depth to it.

The main reason looks to be centered around the heavy bandwidth requirements of the customised UE3, and Kaos's use of a modified lighting system, both of which impacts on both system's available resources.

A look at Homefront's performance, and it's fair to say that most of these compromises are based around getting the game up and running at a relatively smooth frame-rate - at the usual target of 30fps.

As is now standard practice here at IQGamer, we've put together an analysis video showcasing performance across a range of scenes from both versions of the game.

The results are hardly complementary, revealing a slew of frame-rate and screen tearing issues pertaining to both builds. What's clear however, is that across the run of play the 360 game manages to maintain a smoother frame-rate, but tears far more often as a direct consequence. Whilst on PS3, the game drops under the 30fps mark slightly more frequently but features a still noticeable, although reduced amount of tearing.

Performance profiles differ across both platforms. The 360 game runs without v-sync and an uncapped frame-rate - thus we see near constant tearing as the engine delivers loads of unfinished frames to be displayed. But this results in the smoothest controller response possible outside of the game slowing down. By contrast, on the PS3 Homefront employs v-sync, but simply drops it when the game goes below the capped 30fps update. In fact, the game could well be soft v-synced (whereby tearing constantly occurs in the overscan area at the top of the screen), whilst doing the same thing.

Looking at the video it's pretty obvious that both versions constantly fail to meet the targeted 30fps without throwing out out scores of incomplete (torn) frames. Although the game does stay mostly around the intended level - on PS3 at least. The 360, with its uncapped frame-rate is the smoother of the two. But this comes at the expense of visibly more screen tearing throughout the entire experience. Whereas, on the other hand the PS3 game features more frame drops (particularly in heavy scenes), but with less intrusive tearing.

All in all, performance on both formats comes as a disappointment, especially given the trade-offs made in order to ensure as smooth an experience as possible. Unsurprisingly, the PS3 benefits from having slightly smoother controls given its more stable frame-rate. However, when things get busy the opposite is true, making it six of one, and half a dozen of the other in this case.

Far more impressive, is the game use of lighting and the amount of atmosphere it provides. When combined with the sense of scale, and detail of the surrounding environment, it goes along way to sucking you into a world swamped in turmoil. Lens flair is just the one of the initial focal point of the game's lighting implementation, whilst the range provided by the use of HDR delivers ample contrast to the scene in light or dark areas.

The 360 also benefits further in getting extra depth provided by what looks like additional light occlusion, which in turn seems to accentuate the game's use of SSAO. By contrast, while the PS3 game still features plenty of depth also, SSAO has less of an impact on the scene. This can be seen above - not only does the PS3 version appear brighter, but in corners where all three walls meet, there is significantly less in the way of ambient shadowing in some scenes.

In addition the game's use of SSAO on both platforms is distinctly buggy. A noticeable halo effect can be seen around characters as they stand near walls and other objects, along with various environmental objects too as you approach them from differing angles. Additionally, this haloing can also cause shadows on characters to flicker and glitch in and out of view on occasion.

Homefront is a pretty interesting idea, with a potentially engrossing premise and certainly the right artistic design, but one might indeed wonder whether or not Kaos have actually chosen the right tech to do the job properly.

Certainly, a few things stick out from the muddy-looking mess the game sometimes seems to resemble. The lighting for example, in combination with the detailed environmental construction and the game's musical score certainly creates a sense of immersion. And the motion blur/screen distortion effects add impact to the combat when pinned down and being fired upon. But this is continuously counter-balanced with a fuzzy, upscaled framebuffer and blurry looking low resolution effects.

The very same thing applies to both the Xbox 360 and PlayStation 3 games. While 360 owners benefit from having higher levels of AF and additional lighting, plus anti-aliasing, on the PS3 we see better texture steaming and what amounts to a more consistent frame-rate - despite larger drops when the engine is put under load. In which case it's pretty hard to recommend one over the other, or either version in general.

In conclusion, I'd perhaps say that the PS3 delivers the most consistent experience overall. The lack of AA doesn't harm the game as much as it would in other titles - due to the heavy upscale making things look rough on both - and the missing lighting doesn't always dramatically change every scene. But in terms of performance, the steadier frame-rate and lesser amount of screen tearing is a bonus, even if performance under load suffers.

Perhaps, rather than fighting over which version is 'the' one to go for (when neither are great), you should instead think about which version your friends will be playing online. The campaign in Homefront is definitely a second-tier experience - multiplayer online is exactly what this game was made for. And in that respect therein is where your final decision should rest.

Once again, thanks go out to Richard Leadbetter for use of Digital Foundry analysis tools.

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