The Making of Killzone 3

Guerrilla walks Digital Foundry through its latest technical miracle.

Feature by Richard Leadbetter Technology Editor, Digital Foundry

Published on March 5, 2011

The use of these cinematics pushes the amount of space required for the game from around 13GB up towards the 25GB limit of a single-layer Blu-ray disc. However, the final game is a few megabytes short of a colossal 42GB - and that's all down to the support for full stereoscopic 3D. Every single cinematic is actually being rendered and encoded into Bink twice - first in 2D, then in 3D.

The Guerrilla Games team got to see some early 3DTV displays relatively early on during the production of Killzone 3 and were very enthusiastic about the potential.

"We got light of some 3D research going on and got to play with some prototype hardware which really impressed us. We got offered the opportunity to do it, played with the numbers a bit and then decided to go for it. We're always up for a challenge and this all seemed very promising," van der Leeuw recalls, after initially thinking that implementing 3D into Killzone would be "madness".

"Our basic technical approach for 3D was building on the work we did for split-screen. We knew we were going to have to run the renderer twice for two players looking in completely different directions with no coherency between them. We must be able to use that technology and optimise it to pieces if we have two eyes looking in the same direction, right?"

Of all the console first-person shooters out there, Killzone has always tried to be the most immersive. Killzone 2's look, and crucially its feel, was all about the sensation of making the player feel like a real person in the middle of an unimaginably dangerous battlezone - the perfect scenario for 3D. Not only that, the range of locations being planned for the sequel would also benefit immeasurably from the 3D treatment.

"3D is all about immersion, feeling that you're really there, forgetting you're sitting on the couch, being on Helghan and wanting to get off the planet. There is such a difference between a vista looking out over an icy landscape on a flat screen, or in 3D where 3km viewing range feels like 3km," van der Leeuw explains.

Similar to the techniques used in Call of Duty: Black Ops, Guerrilla decided on a full 3D implementation - true stereoscopy from start to finish - in contrast to the reprojection techniques being used in the forthcoming SOCOM 4 and apparently in Crysis 2, where a single 2D image is processed via depth data into discrete images per eye.

Digital Foundry analysis of Killzone 3 gunplay shows that while there is a performance penalty in rendering stereoscopic viewpoints, often the gap between 2D and 3D is relatively small.

"This allows us to pull depth separation apart much further and prevent the layered feeling other techniques have. We also get proper stereoscopic reflections to boot and we can be much more free with things like depth of field," enthuses van der Leeuw.

"The real trick of 3D is to not make it fall apart. Most people like 3D, but when something is off - your crosshair 'feels' unnaturally placed, you gun feels like it sticks through the wall, something you try to focus on stays blurry - it breaks for people. And when it breaks, it breaks the immersion."

The Killzone 3 team achieved this by scaling depth perception dynamically, sometimes with the game code in control, sometimes with the artists themselves directly manipulating the 3D cameras. This combination helped ensure that the illusion of 3D is maintained and not compromised, making it feel significantly more immersive and "real".

Reducing controller lag was a key priority for Guerrilla in Killzone 3. High speed cameras were used to physically verify improvements to the game code, while internal code was added to track events from the initial button press to its exit from the RSX - you can see this system in action in these exclusive shots.

The 3D team at Evolution Studios in Liverpool hasn't finished its work with the new stereoscopic format - in fact, it's expanding on it. Facial motion tracking via PlayStation Eye is being used to control the view generated by the game, a process the team has termed "holographics", and, in PlayStation Move, Sony already has a remarkably flexible 3D controller.

Guerrilla is following these proceedings closely, acknowledging the raw potential of the concept but remaining coy on any future applications, merely saying that it is "always on the lookout for things which will make the experience more immersive".

In the here and now, the studio continues to support its latest game while working on other future projects, including games disassociated from the Killzone franchise. Back in 2005, the infamous Killzone 2 "target render" displayed at E3 was met with disbelief and derision from both press and gamers, but the final game actually surpassed the quality of the CG cinematic in many ways.

Bearing in mind that the team raised the bar technologically so much this generation, we were curious to discover whether Guerrilla was working on a brand new engine, or whether it would continue to refine its existing tech.

"I don't think we'll be creating a brand new engine for this generation. We're pretty close to what you can achieve in this particular direction, although there's always room for improvement," muses Michiel van der Leeuw.

"That doesn't say we can't do anything really fresh. We're going to be doing more than just Killzone in future and new ideas lead to new techniques and fresh experiences."

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