While Epic’s Unreal Engine 3 may be a robust middleware solution, its out-of-the-box state hasn’t quite satisfied the needs of BioShock developer Irrational Games. Although the studio is using UE3 as a base for BioShock Infinite, several tweaks are being incorporated into the underlying codebase — many of them significant.

According to technical director Chris Kline, Irrational is doing “whatever it takes” to bring the sky-world of Columbia to life. The team has fully rewritten AI routines, giving designers the ability to author their own behaviors, an approach backed by an all-new animation system.

Other enhancements include optimizing the engine for dynamic, free-form environments. “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,” notes Kline.

Also notable is the inclusion of a deferred lighting system that allows for characters and dynamic objects to receive global illumination, based on a proprietary per-pixel dynamic relighting scheme, according to Kline.

Irrational has upped the ante when it comes to sound effects as well, with Kline detailing a new audio pipeline that features “adjustable dynamic range and a fully dynamic mixing system” based on AudioKinetic’s WWise tech. Additionally, the core of the engine is built around a “parallel processing framework” that intelligently scales to the amount of CPU cores available.

“This will let us eke out all the power of the PS3 and 360, and also give hardcore PC gamers something to show off their rigs with.”

While this all sounds mighty impressive, it’s also a harsh reminder that BioShock Infinite isn’t due out until 2012.

You can read Kline’s full post over at the Irrational Games forums.

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