Irrational details Unreal 3 and audio tech within BioShock Infinite

Irrational Games has said on its forums it is using a modified version of Unreal Engine 3 for BioShock Infinite, and even detailed what exactly it has done to the engine, as well as what the changes do to the game's effects.

According to Irrational's technical director Chris Kline, the firm's engineers are doing "whatever it takes" to bring the game's setting to life.

"We're talking about a world where entire buildings are moving around in the sky, you're fighting AIs at 90mph on Sky-Lines as you dangle high above the earth, and racing through vicious weather to rescue Elizabeth while battling your way through hordes of enemies determined to stop you at any cost," said Kline on the forums. "Right from the outset we realized that this was going to be a monumental undertaking on the tech side, but decided it was a challenge that we simply had to take on in order to give gamers the kind of quality experience they've come to expect from Irrational Games and BioShock."

The original BioShock engine was a modified version of Unreal Engine 2.5, but since it was outdated only in terms of how the team wanted to us it, engineers started modifying Unreal Engine 3 for the title.

"Everything in Columbia is capable of moving," said Kline. "The very ground beneath your feet could fall out of the sky at any moment, which makes for some awesome gameplay and visuals but required us to create a completely new technology that we're calling 'Floating Worlds'. You saw a little of this in the gameplay video(s) and you'll be seeing a lot more of it in the future.

"To meet the aesthetic goals of our art team, our rendering gurus had to write a whole new renderer for BioShock Infinite based on deferred lighting and on top of that they've developed a proprietary per-pixel dynamic relighting scheme that allows characters and dynamic objects to receive global illumination."

Kline goes on to char about updating the AI system, the addition AudioKinetic's WWise technology for Infinite's sound, which allows voices to "properly echo down corridors and around buildings" while also reinforcing "a dynamic wind audio system" for the dynamic weather in the game world.

It's a rather interesting post, especially if you are interested in tech. Kline's response with all the details is the 12th post down.

BioShock Infinite is out in 2012.

Thanks, BigDownload, Digital Foundry.