Facebook Logo Twitter Logo RSS Logo
Issue: Volume 35 Issue 2: (Feb/Mar 2012)

Gears of War 3

By: Karen Moltenbrey

Three’s a Charm

Computerized gaming has certainly evolved over the years, thanks in no small part to the current generation of sophisticated, ultra-powerful consoles. As a result, developers are able to fine-tune their titles to take advantage of the processing capabilities offered on these machines. The result? Games that integrate interesting story arcs and compelling gameplay into a title brimming with stunning environments, emotive characters, and complex visual effects. Now, a number of them are also embracing the 3D stereoscopic medium.

In this feature, CGW looks at a trio of games: two “a third release” in their respective series and one a new take on a very popular franchise—and each pushing game graphics to a new level. An exclusive title on the Microsoft Xbox 360, Gears of War 3 from Epic Games offers a stunning culmination to the trilogy as Delta Squad leader Marcus Fenix makes his final stand in an attempt to save humanity from fearsome invaders in this stereo 3D title. In Uncharted 3: Drake’s Deception, Naughty Dog ups the ante in terms of gameplay and graphics quality and technology as fortune hunter Nathan Drake takes players on an Indiana Jones-style adventure in this exclusive Sony PlayStation 3 title, also in stereo. And BioWare redefines the MMO genre with Star Wars: The Old Republic, a fully voiced online game featuring an incredible cast of characters.
 

Gears of War 3

When Epic Games introduced the world to the grizzled war hero Marcus Fenix in 2006’s Gears of War, the developer did so using its new multi-platform Unreal Engine 3 (UE3), developing the game engine alongside the title for the Microsoft Xbox platform. In fact, Gears of War was the first console game to be released that took advantage of all the CG technology that the UE3 had to offer: fully programmable shaders, per-pixel lighting, high-dynamic-range rendering, dynamic shadows, and more. Several years later, it only seems fitting that the developer utilize its latest revision of the same engine to bring Fenix’s struggle to its conclusion.

But make no mistake about it. UE3 had undergone major updates since its debut, particularly affecting the rendering, the AI, the material system, and the lighting and shadowing. As a result, Gears of War 3 is by far the most technically advanced title to run on the UE3 to date, due to the continued refinements that squeeze every last bit of power out of the console for a game that looks better than its predecessor, even though the core hardware remained the same. To this end, Gears 3 is once again a showcase of sorts for the engine’s technology, as well as the artists’ creativity.


Epic Games culminated the popular Gears of War saga with Gears of War 3, pushing the Epic Unreal Engine 3
to its limit to achieve the game’s rich aesthetic.


In Gears 3, players resume the fight as Fenix, leader of Delta Squad. The story takes place a year and a half after the fall of the last human city in the previous title, as the war against the Locust rages on, only now a new foe, the Lambent, have emerged and threaten what’s left of the human population. As the Lambent invade, Fenix and his followers find refuge on the CNV Sovereign, an abandoned aircraft carrier that has been turned into a village of sorts. Upon learning that his father is alive at a secret base called Azura, Fenix and his crew make their way there, where the elder Fenix has created a solution to rid the planet of its invaders, but not without serious consequence to the father, who sacrifices himself to save humankind.

“It’s a big blockbuster action game with crazy combat and visceral action,” says Wyeth Johnson, lead artist. “We try to blend that type of gameplay with interesting cinematic events and tell an interesting story in the process. So we use the technology that is available to us in the Unreal Engine 3, to make sure that these experiences are as polished and epic as possible.”

The use of modular sets for the infrastructure when applicable made it possible to create custom hero pieces.


The environments in Gears 3 were built using 3ds Max and textured in Photoshop and ZBrush for organic work.
The use of modular sets for the infrastructure when applicable made it possible to create custom hero pieces.


In particular, the Epic team focused on the lighting quality. They wrote a new global illumination solver, called Unreal Lightmass, which provides high-quality static lighting with next-generation effects, such as soft shadows with accurate penumbrae, diffuse, specular inter-reflection, and color bleeding. Moreover, subsurface scattering and other parameters in the tool help make the characters’ skin look more realistic, while enhanced specularity makes metal surfaces look more like metal.

“We looked at the game and asked ourselves, How can we use this lighting to make the environments feel more realistic, more grounded? Therefore, we focused most of our effort on the lighting and shading, to bring the visuals to the next level,” says Johnson. “We looked at our previous games and decided that we wanted more of a natural, soft, slightly more colorful and filmic look, so we tailored the technology to exactly match the needs for this type of game and worked with the tech team to make that happen.”

Creating Characters


The Gears 3 characters were modeled with Auto­desk’s 3ds Max and Pixologic’s ZBrush, with the modelers creating basic forms and proportions in Max, and then bringing those high-polygon models into ZBrush to generate near-infinite levels of sculpted detail. Next, they brought the high-poly model back into 3ds Max, where they created low-poly in-game-resolution models. Then they used the high-res, high-poly version to generate normal maps for the low-res models, which gave them the look of the high-detailed, high-resolution asset.

Animation was achieved using a combination of Autodesk’s Maya and motion capture—the mocap, acquired by a Vicon system, was used as a kind of first pass. It was then brought into Maya, where the group animated on top of it. “Motion capture gives us natural human motion, but it is not that good for the small details, like animating hands or creating gestures or facial animation,” says Johnson. “The animators want total control of those things to elicit emotions, so motion capture offers a rough inspiration and is brought in as a guide and then cleaned up, while the real emotional acting and finer details are done by hand by the animators.”


The game includes creatures of all sorts. Some are bipedal and have humanoid characteristics, while others
are more fantastical that pushed the imagination of the artists.


The motion capture would provide large-­frequency detail—for instance, multiple characters interacting with one another or an object. Low-frequency motions and certain macro-motions were animated by hand in Maya. But nearly all the motions were a result of hand-polished animation atop the mocap data. “I don’t think there is a single piece of motion-capture data that was used straight out of the system. Everything was in some way polished or cleaned up by our team,” Johnson says.

Epic employed its own motion-capture stage for acquiring the movements. The Vicon motion-capture system consists of 36 cameras used to track optical data, as well as four video reference cameras, all running through Vicon’s Blade and processed with Autodesk’s MotionBuilder, too. The final animation was done in Maya, where the characters rigged. “We have a team of animators here that get realistic human emotion out of what is essentially a puppet they are manipulating,” notes Johnson.

Players and industry pundits have praised the game for the quality of its animation, and Johnson agrees that the team made aggressive strides in this area. As he notes, the artists wanted as perfect an animatable face as possible but accomplishing that in a very generic way without a lot of specific characteristics (male/female, young/old, and so forth). They created universal head geometry—a big change from their previous work—that would give the animators the control they needed while still enabling them to reuse the base geometry across a large portion of the characters.

To accompany the neutral heads, they devised special universal facial rigs that Johnson compared to those used by a film studio for a proxy mesh to animate displaced high-res movie models—Epic even hired animators from the film industry to contribute to this facial rig.

“The goal was to use as few bones as possible [in the universal rig], but in the most intelligent way possible, so a lot of it came down to allowing us to create ancillary detail through the blending of normal maps to create facial detail and to expose features like wrinkles, things that are hard to do in real time within games.” The riggers tried to avoid putting too much geometry and complexity into the universal facial rig, instead making it a clean, easily deformable asset the animators could work with, and if they wanted high-frequency details, like wrinkles around the eyes, forehead, and mouth, then that was done by blending in additional normal maps.

“There’s always a trade-off between quality and the time invested,” says Johnson. “The less time we spent on setup, the more time we had to polish the visuals and increase the quality of the animation.”

Skin and Hair


For the human characters’ skin, the artists used subsurface scattering that was blended inside the node-based material system of UE3, where the artists were able to manipulate the surfaces throughout the game. According to Johnson, there is custom skin falloff properties—texture maps that define the density of the skin and the falloff.

“The artists have almost total control over the system inside the Unreal Engine 3, so this area is very much art-driven rather than code-driven. The code gives us the power, but the artists go in and manipulate the parameters to create some very detailed approaches as to how we handle the skin pores and how they contribute to the specularity on the skin,” Johnson explains. “We are careful about painting a diffuse map that is flat and lets the real-time lighting do the heavy lifting.”

 Seeing in Stereo


Gears of War 3 includes a stereoscopic mode for 3DTVs, made possible through TriOviz for Games Technology, which enables smooth stereoscopic 3D conversion of video games and requires glasses with complex color filters and dedicated image processing that allow natural color perception.

The technology was integrated into the Unreal Engine 3 in 2010; the SDK works with the Xbox 360, as well as the PS3 and PCs. All the gameplay and cinematics contain the stereo 3D support, as does the split-screen play. (The player can opt for non-stereo mode.)

“Fortunately, we didn’t have to do a lot of additional work other than make sure we had custom code to properly handle things like the user interface and other small things,” says Wyeth Johnson, lead artist. “The system is very robust, and we could take advantage of it without too much development, so that let us focus on the core gameplay experience, while the underlying technology was able to do its splitting and stereoscopic results without us having to go in and hand-create too many of those stereo experiences.”

Hair, like skin, is always difficult to do in games, so for Gears 3, the team added specific features to the engine for creating more realistic hair. The artists primarily used a series of overlapping cards; however, this resulted in lighting issues: All the overlapping cards have translucency sorting relative to one another, making it difficult to get the specular sheen or an anisotropic specular result that runs down the hair. To avoid this, the group employed custom sorting methods that allowed the artists to go in and tweak the cards, to make sure all the overlapping sheets interacted with one another. Also, they employed translucency lighting models that aggregated the effect of those layers into a result that is very soft. “So rather than have all these overlapping polygons fighting with each other, which is a very common result in previous generations of games, in Gears of War 3, we were able to achieve a more cohesive look that is more realistic for the hair,” says Johnson.

The stubble on the characters’ faces, however, was baked into the diffuse maps of the characters. For longer facial hair, like beards, the artists employed the same process as they did for the head hair. For the most part though, the characters are relatively clean-shaven.

The game also incorporates some simple physics simulations for things like ponytails, coattails, and dangling pieces of cloth—although this was used sparingly because the technology is performance-intensive. Nevertheless, when there was an object that needed to react in real time to a physics simulation, the artists were able to rig it with a chain of bones and simulate the motion in real time on the characters.


For the human characters’ skin, the artists used subsurface scattering that was blended inside the node-based material system of the Unreal Engine 3, where the artists were able to manipulate the surfaces to achieve the desired results. The skin has custom falloff properties, making it look more realistic.

“A large portion of our characters have those physics assets integrated into them, whether it’s a big, crazy flap of cloth or something subtle like a canteen that jiggles slightly when a character runs,” says Johnson. “We would use it when it gave us the biggest bang for our buck.”

So, which characters were the most difficult to deal with? Marcus Fenix, says Johnson, for the fact that the artists had done two previous Gears iterations in which he didn’t change much. “When he moved to Gears of War 3, the game takes place in the heat of summer, and we wanted to take off his bulky armor plates and expose his skin. Plus, we had new technology to take advantage of features like better hair, better skin shading, and better lighting,” he says. “However, we still had to be careful. When you want to take a character that you consider the pillar and main focus of your franchise, you can’t alienate people who are used to what he looks like. Yet, you still want to make a fresh experience for the player and show off the new features of the game. It was tricky to find that right balance for the old Marcus Fenix and the new one.”

Aside from the human characters, the title is filled with creatures—from Locust to Lambent. The Locust have some humanoid characteristics, are bipedal, but are feral and more visceral than the humans. The Lambent are mutated forms of the Locust; they are found in many forms, from the more humanoid-like to giant, more fantastical monsters with long tentacles, and everything in between. “We have all manner of the traditional monster, some really over the top,” notes Johnson.

Construction Challenges


Gears 3 ’s environment work started with concept art. According to Johnson, in this wrap-up to the series, they wanted to be more careful about the emotions of the player, originating at the start of the story and continuing throughout the game. For each environment, the concept artists came up with color styles and concept art that reflected how the player was meant to feel in the particular settings. Once construction began, every decision was influenced by that mood and the story arc. “It makes for a more believable environment because how the characters interact with each other and how the gamer sees the world matches the emotion we are trying to elicit in those environments,” says Johnson. “That is why everything feels a bit more cohesive and real because we put more emphasis on that kind of environmental design for Gears of War 3, and it absolutely paid off for us.

Almost all the environments were built using 3ds Max and textured in Adobe’s Photoshop. ZBrush was employed for damage passes and other organic work. As Johnson explains, artists would generate concept art for a given environment to establish a look and feel, and then would look at things like the infrastructure—floors, walls, ceilings—and break those out from the concept art into a modular set. In short, they would determine which pieces could share resources or model data/textures, thereby freeing up space and time for the creation of hero pieces that were custom-built and new to the game.

“We share as many resources as possible so we aren’t spending processing power to render the infrastructure of an environment. This allows us to create unique, over-the-top set pieces that are only possible using modular environmental design,” Johnson adds.

The game contains 15 environments, all vastly disparate—from the Locust dead lands full of bleached, exposed bones, to blowing sandstorms, areas overrun by glowing creatures, and more. “By far these environments in Gear of War 3 are the most varied we have ever done here at Epic,” says Johnson. “There’s a broad range, and the look of the lighting, to the mood and feel that each environment elicits, is amazing. I think it is the most mature effort we have made in creating a space in a world that is fully realized. It makes the player feel grounded and like they belong in that world, as opposed to an outsider looking in.”

The game opens on the deck of the aircraft carrier that has been overtaken with people escaping the threat. The hardest environment to create was the so-called Raven’s Nest, a small floating city made out of the carrier and two other ships, due to its mechanical and organic complexities. “We had to make it believable but figure out what the ships would look like in the Gears of War 3 universe, and what they would look like when taken over and the decks used to grow crops and the torpedo tubes used to raise chickens,” says Johnson.

When designing the environments, the artists like to start with places and objects that would feel familiar to the player, and then they bring their own sensibilities to it to make it feel like it belongs in Gears of War. For the ships, they took a field trip to see the structures in the real world. Then they took those inspirations and mapped them to the game’s aesthetic to find a middle ground so that the object still feels familiar but is stylized appropriately for the game.

Another difficult environment was the charred setting near the end of the game. It’s dreary and overbearing, with ash swirling through the air and shafts of light cutting through destroyed buildings. “It was an artistic challenge to elicit the right mood of hope and despair,” he adds. A large part of the team’s research focused on new lighting technology, using real-world references, white papers on how lighting behaves, as well as how a person’s eyes respond to light. They also drew on the group’s own experiences with photography. “We used a lot of references from the real-world and compared that to our results inside the game, to be more representative of what happens in the real world. We did a lot of reference and source gathering to figure out how that all works so we could reproduce it faithfully inside the game technology,” explains Johnson.

Of course, a game like Gears 3 contains physics simulations to make objects collide, handled through Nvidia’s PhysX solver and created at the core of UE3. This technology was used to generate the character ragdoll dynamics. It also enabled the artists to add fracture effects to static meshes to simulate destructible environments. In addition, the game contains VFX simulations—colliding particles, Maya fluid sims that are baked to animated textures to generate explosions. “We use a lot of technology—high-end film-style effects—that run well on the Xbox 360,” Johnson says.

For a broad surface of water, the team would use vertex shaders to create macro animations of the surface of an ocean that is programmable and controllable on the art side. They would also do large-scale motion through the vertex shaders, but for high-frequency detail, they would use interacting normal maps in combination with real-time or pre-baked reflections for realistic kinds of objects. They did not, however, do fluid simulation directly in Max or Maya, except for occasional water splashes—and that would be baked to an animated texture that they could then use for splash effects within the particle system.

“The visual effects in the game look better than anything we’ve ever done. We put a big emphasis on them this time around,” Johnson says. “We have lots of post-process aspects to the effects that we didn’t have in the past--like radial blurs on explosions, integrated camera shakes, lens flares, and effects—that all contributed to the feel, the visceral nature of our particle effects. We focused on high-resolution, animated simulations for things like smoke and fluid simulations that we brought in as high-res, animated textures. And then we have vertex particle lighting in UE3 that we utilized heavily. When a particle system like an explosion happens in direct sunlight, it feels like it is illuminated by that lighting, and if it happens in shadow, it darkens down and does the right thing to make it feel more grounded. Our visual effects have taken a huge leap forward in Gears of War 3 for that reason.”

Gears of War 3 is the spectacular conclusion to one of the most memorable and celebrated video game sagas. The Gears of War series began its journey on the Unreal Engine 3, one of the most popular game engines licensed by outside developers as well as those outside the gaming industry. Yet, when UE3 is utilized by developers within the same company who are intimately familiar with its technology and capabilities, the results take a quantum leap forward.

As a result, this last iteration has taken the Gears saga well beyond the previous releases with its intensive gameplay, compelling story, and its fine graphics style, making it a fitting end to such a cutting-edge series. n

Karen Moltenbrey is the chief editor of Computer Graphics World.
Back to Top
Most Read