August 2, 2013

Critically Acclaimed BioShock Infinite Powered By Unreal Engine 3 Technology

By John Gaudiosi

Irrational Games has another hit on its hands. “BioShock Infinite” has been amazing critics (with a 94 rating for PC and PlayStation 3 and a 93 for Xbox 360) and gamers alike. The sequel to the critically acclaimed blockbusters, “BioShock” and “BioShock 2,” has taken advantage of years of technology advancements from both Epic Games, which built the Unreal Engine 3 game engine, and the development team at Irrational Games, which has added its own additions to the core engine to bring the floating city of Columbia to life.

“Our Core Technology team, led by Steve Ellmore, and our Gameplay Programming team, led by John Abercrombie, have replaced or heavily modified vast portions of Unreal Engine 3 for BioShock Infinite,” said Chris Kline, Technical Director at Irrational Games. “A few examples of systems their teams developed include AI, rendering, audio, animation, entity movement, collision detection, user input. Other systems were deeply modified such as physics and content streaming.”

The developer has also made extensive architectural changes to allow many core engine systems to run in parallel on separate SPUs or CPU cores. A small selection of systems that they have running asynchronously (depending on the platform) include collision detection, ray casting, sound propagation, garbage collection, Sky-Line geometry extrusion, spline proximity tests, AI suppressive fire calculations, data compression/decompression, animation transform and blending, audio processing, particle generation, SSAO, command buffer generation, rigid-body physics and cloth simulation.

BioShock Infinite - Liz OnLine

“In many cases we needed to come up with entirely new systems to create the world of BioShock Infinite,” explained Kline. “For example, we developed a technology we call ‘Floating Worlds’ to allow all of Columbia’s buildings, zeppelins and barges to be in constant motion without affecting performance. Another example is the ‘Pattern Matcher,’ a system that continuously analyzes the state of the game world over time to detect patterns of behavior. This allows us better understand the kinds of conceptual situations that the player, Elizabeth and AIs are in involved in at any given moment, so they can behave and speak in a context-appropriate fashion.”

One of the more impressive technological accomplishments in “BioShock Infinite” – and there are many – is the computer-controlled character, Elizabeth. She actually has multiple roles in the game. In addition to being what Hitchcock would call the MacGuffin, in the sense that she’s the one that the various factions are pursuing in this game, she has the ability to tear through time and pull elements like gun turrets from the future back to 1912. While she’s the one the player, as Booker DeWitt, is rescuing, she actually plays a huge role in helping throughout the interactive storyline.

In addition to the aforementioned technology changes, Kline said almost all of the original UE3 gameplay code was rewritten and the vast majority of UnrealScript code was removed. They extended the Unreal Editor toolset rather than replacing it, but very few systems remain “untouched.”

BioShock Infinite

The Unreal Engine enabled the original world of Rapture to come to life leagues beneath the sea. Ken Levine and his creative team in Boston decided to venture into original territory with Columbia, while tackling deep new political themes with the ultranationalist Founders and the rebelling people’s movement known as the Vox Populi, and taking a very different look at an alternate 1912.

“It’s a very different engine than we had before,” added Levine, founder of Irrational Games. “For better or worse, we had to throw out everything we had in the first game because we could not build this new game on it. That engine was really good for building these tight corridors and these underwater, underground structures that would appear. But with these big open spaces where you’re fighting 10 or 12 enemies at one time, that’s something for which we needed to build a new piece of technology. We couldn’t have done it in the old engine, but our action has always been a company that’s creatively driven and the technology is designed to support creative effort.”

Levine said his team has amazing technologists who are always willing to figure out how to solve the toughest problems. That’s how the sky lines were built. The creative team dreamt up cool new gameplay elements, such as the rollercoaster-like Sky-Lines system that’s used to transport cargo, and the technology team built the necessary code to bring that fun new mechanic to virtual life.

“It was really challenging but once you have that visceral feeling of being on those Sky-Lines and figuring out how they would work in this world, how they would look in this world, how they would feel in this world, it got really exciting for us and we’re really happy with how it turned out,” said Levine.

With four years in development, using Unreal Engine 3 did save the team time in bringing this latest masterpiece to PC, Xbox 360 and PlayStation 3. The team’s familiarity with the technology from the original “BioShock” also helped with introducing new code and new gameplay to the equation.

Boy of Silence - BioShock Infinite

“We’re talking about a world where entire buildings are moving around in the sky, you’re fighting AIs at 90 miles per hour 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. “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.”

As the raves from fans and the most nitpicky gaming press have expressed, Columbia is unlike any game world that we’ve ever seen. The “Floating Worlds” technology Irrational created keeps players on the edge of their seats at all times, since the very ground beneath you can fall out of the sky at any moment. Add in the armed mechanical enemies like the Gatling gun-armed Motorized Patriots and the giant Songbird and this is likely the least of players’ worries as they progress through the 12 hours of story.

The open world looks gorgeous, or even unreal, and its bright open outdoor spaces are in stark contrast to the dark and gloomy, claustrophobic environments from the original BioShock. Kline said his rendering team created a new deferred renderer based as well as a proprietary per-pixel dynamic relighting scheme that allows characters and dynamic objects to receive global illumination. It’s this type of new technology that brings this unique interactive world to gamers, creating a canvas on which Levine and his team have painted an intriguing story with many layers. With his creation now complete, except for the upcoming DLC, Levine is looking forward to the future of game development.

“What excites me are the unknowns,” said Levine. “I think a lot of people would get very nervous about change, but I think it keeps us on our toes. We have to keep changing. When I started this I was making half-million-dollar budget PC games and now we’re making these big-budget PC and console titles, and that may change again. Who knows what the future may bring. Maybe we’ll have to readjust and rethink how we do things, but I find that exciting, and I love understanding how the space is changing. I play every kind of game and if you think today is going to be tomorrow, or you think yesterday is going to be tomorrow, you have a real problem. Tomorrow is tomorrow and none of us really know what it is, but that can either cause you anxiety or you can enjoy it.”

Gamers are certainly enjoying “BioShock Infinite,” which has become one of the best-reviewed Unreal Engine games of all time. With this tech at its very core, it’s the creative minds of Irrational Games that have pushed both storytelling and the ability to create brilliant new worlds to new heights, literally. “BioShock Infinite” showcases why current generation consoles can still bring amazing experiences to life with the perfect marriage of technology and creativity.