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Issue: Volume: 31 Issue: 9 (Sept. 2008)

Force To Be Reckoned With


If you believe Roger Ebert’s old adage that a story is only as great as its villain, then you’d have to agree that playing through the stories in most computer games can seem predictable and preprogrammed. Truth be told, that’s exactly what their villains are—preprogrammed and predictable, incapable of truly matching the player blow for blow and, ultimately, deflating any sense of accomplishment.

But now LucasArts, armed with a relatively new technology called Euphoria from NaturalMotion, is about to draw the curtain on what many are calling “the silent era” of computer games and usher in a new era, one in which nonplayer characters (NPCs) are given a “voice” and a will of their own. It’s a monumental milestone, one being likened to the introduction of sound in motion pictures. For the first time in computer game history, the actions of NPCs will no longer be pre-programmed or pre-animated, but governed by Euphoria’s Dynamic Motion Synthesis (DMS). Under the influence of DMS, characters’ movements will no longer be driven by pre-canned animation cycles, but by a motor-control and nervous system that responds intelligently to sensory input about the environment. 

When Star Wars: The Force Unleashed is released this month, thousands of stormtroopers, those mindless minions of the Empire, will actually have a mind of their own. For example, in one of the game’s celestial settings inside a massive orbiting TIE Fighter construction facility, stormtroopers stand perched atop suspended metal platforms and bridges. When they’re thrown off balance by an invisible force, they cling for dear life to anything within their reach­­—handrails, ledges, cables, even each other. And when a bridge collapses, arcing downward, they struggle frantically to gain a foothold, shifting their weight from leg to leg in order to gain their balance before plunging to the depths below, even clutching their heads as they fall.

All of those attempts at self-preservation are unique; no two reactions to a situation are ever the same. In fact, when LucasArts first programmed the stormtroopers with Euphoria, they were so astonishingly adept at navigating the hazards of their environment that the crew had to “dumb down” their artificial intelligence to make the game more playable.


Star Wars: The Force Unleashed is a solid example of next-generation gaming in nearly every aspect.  Players battle Felucian warriors on Rancor (shown above) and other creatures that can act independently in the interest of their own self-preservation.


Euphoria is not the only revolutionary software set to debut in The Force Unleashed. As digital characters finally come to life, so, too, will the physical world around them, thanks to Pixelux Entertainment’s Digital Molecular Matter (DMM). A breakthrough in material simulation, DMM will endow almost every object in that storied galaxy far, far away—be organic, inorganic, rigid, or soft—with the properties of its real-world counterpart. The glass windows of Star Destroyers will shatter like glass; the trees of Kashyyyk will splinter like real wood; the metal wings and hulls of TIE fighters will warp and dent like real metal; the stone igloos of Tatooine will crumble like stone; and Jabba the Hut’s blubberous rolls of fat will jiggle and jostle like gelatinous goo. None of those effects are modeled or animated; they are procedurally generated by DMM, a unique material physics simulation that, along with Euphoria, imbues the virtual world with a sense of potentiality and possibility unlike anything gamers have ever experienced.

Imagine being trapped inside a trash compactor as the walls begin to converge. Knee-deep in a pool of garbage, you’ll have to think hard about how to brace the walls when every piece of debris compacts according to its own virtual density, including that slimy snake monster with the periscope eye coiling around your feet.

Successfully integrating these two programs into a game was an engineering nightmare, one complicated more so by the fact that both programs had to also interface with Havok’s physics engine, which was used for collision detection and some rigid-body simulation. The headaches were endless. A world fully enabled with DMM—wherein a Jedi or Sith Lord could slice through every wall, door, cable, and boundary with a lightsaber—created too many problems for level designers to be practical. Sometimes the player, using the Force, would throw a Euphoria-enabled stormtrooper, who’s clinging to a Havok-programmed cargo container, toward a DMM-enabled wall with such velocity that the game engine couldn’t make the calculation fast enough, so the stormtrooper would sail right through the wall.

Moreover, Euphoria’s biomechanical simulations of human movement are based on real-word math and physics, so applying an unreal power such as the Force to their bodies would often stretch and tear them apart. Solving these problems would require a new game engine, one developed within ILM and LucasArts’ integrated Zeno production pipeline. So, how did LucasArts, a fading player in the gaming field since 2003, suddenly re-emerge at the leading edge of the industry? The turnaround began with Jim Ward, former head of LucasFilm.

Writing the Next Chapter
After bottoming out with a string of uninspired Star Wars titles and sinking revenues, George Lucas appointed Ward as president of LucasArts. Ward fired a quarter of the staff and split the remaining crew into two teams: one tasked with producing a new Star Wars title, the other a new Indiana Jones game (now set to be released in 2009). To helm the Star Wars title, Ward chose Haden Blackman, a 10-year veteran at LucasArts who had worked previously as a writer for such games as the Star Wars: Knights of the Old Republic, Star Wars Galaxies: An Empire Divided, and Star Wars: The Battle for Naboo. This time, Blackman had to deliver a story that would have as great a seismic impact on the Star Wars mythos as the new technology would have on the art of gaming.

To this end, Lucas charged Blackman with developing a story that would bridge the 18-year gap between Episode III: Revenge of the Sith and Episode IV: A New Hope. Lucas’ only stipulation: Darth Vader had to be integral to the story line. The 35-year-old explored a number of possible narratives, but most of those ideas would have left the player without a lightsaber and, worse, access to the Force—two things the team wanted. As for Lucas, he encouraged the crew to focus on creating a new cast of characters.

After seven months of hammering out a plotline, Blackman returned to Lucas with a story about a secret apprentice taken under the wicked wing of Darth Vader, someone who could, unlike a Jedi, wield the full power of the Force with total moral abandon. Lucas loved it, especially a demo film of the apprentice plucking an Imperial Star Destroyer out of the sky and plunging it into the ground. “That’s perfect. Go make that,” said Lucas. Like the feature films, the game’s plot is a story of redemption, and the conflict culminates with a plot twist about the formation of the Rebellion and the mystery of the hero’s apprenticeship that’s as thunderously surprising as the “I am your father” turn from The Empire Strikes Back.

In keeping with the saga’s roots in Joseph Campbell’s classic distillation of mythic structure, Lucas also urged the team to develop a comic sidekick and a love interest for the hero. With the apprentice’s goal of seeking out and executing Jedi across the galaxy at Vader’s behest, the team had to then develop Jedi adversaries to oppose him.


The long-awaited game title, with its rich environments and smart characters, bridges the nearly 20-year gap in the story between Episodes III and IV in the film series.


New Cast of Characters
One of those adversaries is Master Rahm Kota—a grizzled, tough-as-nails general trained by Qui-Gon Jinn and Yoda—whose own emotional arc takes him from a disgraced and defeated outcast drowning his sorrows in an Ugnaught bar to a man with renewed purpose in the tutelage of the apprentice.

Also on the apprentice’s hit list is Maris Brood, a young Jedi wielding dual lightsabers who, after her master is murdered, flees to Felucia, a giant mushroom planet, where she vows to take revenge upon Darth Vader. There, she’s discovered by Jedi master Shaak Ti, rescued from her vengeful “dark side” emotions and trained along with the other Felucians for an inevitable confrontation with Vader. Maris Brood becomes a Padawan to Shaak Ti on Felucia.

“The two make a great contrast; the hard-edged, dark-limned Maris Brood stands apart from the gentle, contemplative Shaak Ti,” says Blackman. “Maris’ role also grew once we cast an actor for the part. Adrienne Wilkinson brought such strength and performance to Maris that her role expanded with more dialog.”

Serving as the love interest is the beautiful star pilot Juno Eclipse, who’s played by Nathalie Cox. She’s handpicked by Vader to test his loyalty and self-control as she ferries him to and from his various missions aboard an advanced spy-ship called the Rogue Shadow. Finally, as the comic sidekick, there’s Proxy, a prototype holodroid that looks much like C-3PO.

With the cast, the settings, and the story in place, Blackman and his team set out to create what Lucas has called the “next great chapter” in the saga.

Vehicles, Environments
With this story line set in the interim between Episodes III and IV, LucasArts was responsible for re-creating and sometimes forging early designs for the iconic Imperial vehicles, such as the TIE Fighters and the All Terrain Armored Transports (AT-ATs), those large, four-legged walkers seen on the ice planet Hoth or the forest moon of Endor. To do so, they borrowed many of ILM’s digital assets for the films.

“We used everything from ILM’s vehicles to its characters, including Obi-Wan’s digital double. Our pipeline is such that anything that moves in the game is considered a character. This occasionally caused a bottleneck in the rigging pipeline for objects as simple as a mouse droid or a chunk of a Star Destroyer that needed to detach and fall from the main body,” says art director Matt Omernick.

This rigging bottleneck was fortunately alleviated by DMM, which could generate many of the damage and destruction effects on its own, without excessive rigging. “This is one of the positive side effects of DMM technology and one of the reasons we chose to partner with [Pixelux]. Because the tools procedurally split the mesh into its possible areas of fracture, this saves a modeler from having to build 10 versions of a destructible object. It took a while to get the pipeline running smoothly, but we saw these bene­fits over time,” adds Omernick.

DMM also made fleshing out the game’s myriad environments much easier, especially the towering toadstools and fungal flora of Felucia and the junkyard world of Raxus Prime, which could not be constructed in a modular fashion. When the apprentice uses the Force to push or pull on the plant life of Felucia, the DMM properties—as opposed to spline IK or multiple models—make the leaves bend, sway, undulate, or snap.

“Both Felucia and Raxus were risks for us,” says Omernick. “On one hand, we wanted to create environments never seen in a game. They needed to be organic, large in scale, and composed of materials and substances that showcase the physical properties of DMM. But as we know, the difficulty lies in the level of modularity. Imperial ‘man-made’ environments, like the TIE Fighter construction facility, can be clicked together like LEGOs. They can be tiled, instanced, and reused, which makes them more easily interchangeable and, therefore, easier to iterate. In the case of free-flowing organic environments like Felucia and Raxus Prime, the landscapes are unique, contiguous, and require a level of customization that makes it very difficult to alter if the geo is not working in your favor.”

Although universal destructibility is possible through DMM, gamers hoping to carve a red-hot, molten passage through metal walls, like Obi Wan and Qui-Gon did in The Phantom Menace, will be disappointed. Such freedom created too many headaches for level designers, who opted instead for a world wherein the apprentice could use the force to blow out doors, pluck objects out of the air, and hurl them around.


While the title is ripe with exciting new animation, the stunning environments should not be overlooked. In fact, Pixelux’s material simulation program, Digital Molecular Matter, endows nearly every object within the environment with properties of its real-world counterpart.

Euphoria vs. Animators
“It’s the characters the audience cares about,” George Lucas once said of his Star Wars trilogy. It seems fitting, then, that a Star Wars game would be the first interactive title to introduce Euphoria-enabled characters to the world. As exciting as it may be to match wits with stormtroopers, Jawas, and Rancor monsters that can act independently in the interest of their own self-preservation, it’s disconcerting for the thousands of animators who can foresee their jobs slipping away, or, at the very least, challenged.

Asked to assess the future of animation in games, LucasArts senior animator Tristan Sacramento sees change and a need for animators to adapt to a new workflow. “Euphoria works great as a reaction-based behavior simulator, and there’s a future for Euphoria in games. The amount of randomness and simulated behavior would take a huge amount of animator man-hours to keyframe,” he says. “Because of this, I can see Euphoria replacing ragdoll very soon in the future. With that said, animators’ jobs are safe. A good, solid acting or action performance can never be simulated. These have to be achieved with either motion capture or traditional keyframe animation. Euphoria is in its early stages, and a lot of the tuning is in the hands of the programmers, but the more it evolves and becomes more animator friendly, the greater the performances that will come out of it.”

Sacramento compares the situation with that of motion caption, which, in its early days, was a threat to animators, and it did not provide good-quality data samples. But today, motion capture has been integrated into many game studios and has helped animators work more efficiently and produce great work in a shorter amount of time. “I see the same happening with Euphoria,” he says.


LucasArts used its Clone Cam faciallikeness technology to create lifelike digital facsimiles of the actors playing main characters in the game. Left is a photo of an actor; right is the CG version.


Character Rigging
The rigging began in Autodesk’s Maya, where the characters were outfitted with bones, IK handles, and various deformers and blendshapes. Animators could then hand-animate the rigs or let Euphoria drive them. “Euphoria is able to drive our characters using the key or core components of our rigs, along with their own adjustments, based on the meshes themselves. Everything else, including weighting, cloth, [and armor] animation, is automatically driven on top of that,” says Charles Brahmawong, senior character TD. For the stormtroopers, character TDs created one modifiable rig.

“We actually use a mixture of Euphoria and traditional [keyframed and mocapped] animation for almost everything we do,” says Sacramento. While Euphoria is a big part of the experience, the crew still uses traditional animation as the basis for everything, from establishing the look and feel of characters to creating true character performances. So, when and how do NPCs transition from Euphoria’s procedural animation to keyframed or mocapped animations executed in Maya? According to Sacramento, “the transitions usually lie where ragdoll would happen, usually in areas where there is an action/reaction involved. Most cases occur during a Force push when the NPC loses control of the situation and has to react to his environment.”   

When Euphoria and DMM are in full throttle, the team would often witness surprising and unexpected behaviors from the NPCs—some that would require the attention of engineers to ensure the game did not become unplayable.

“NPCs have a sense of balance. Euphoria can predict oncoming objects and react accordingly. With such environmental awareness, NPCs will hop over objects, duck away from them, or dodge out of the way—whatever it takes to stay alive,” explains Sacramento. “With a mix of all these simulations, you can get many varied results.”

Sacramento also marvels at the NPCs’ proficiency for grabbing ledges or each other in precarious situations. “With tagged edges throughout the worlds, the NPCs will try to reach out for ledges and keep themselves from falling to their deaths. NPCs will also reach for other NPCs for assistance or to save themselves, or to simply be an evil person and take someone else along to their death,” he adds. 

Key Collaboration

With both LucasArts’ and ILM’s pipelines fused under the Zeno production environments, the game developers were able to employ ILM’s digital assets, as well as the studio’s facial-capture and matchimation technology, allowing them to put the performances of lead actors Sam Witwer (the apprentice) and Nathalie Cox (Juno Eclipse) directly into the game. “When [the apprentice] smirks or scowls, you’ll see Witwer’s expressions, digitally captured and applied to a model that bears his digital likeness,” says Haden Blackman, project lead. “It’s very much like how you ‘see’ Bill Nighy as Davy Jones in the Pirates of the Caribbean movies. It’s a new approach for LucasArts, and it affected the way we handled casting for The Force Unleashed.”

In previous games, only the voice mattered when selecting an actor for the vocal performance. “Here, we had to disregard such precedent once we knew, early on, that facial motion capture and likeness capture would imbue our lead characters with life,” adds Blackman. This approach also affected the game’s script; The Force Unleashed script is pared down considerably from that in previous games in terms of expository dialog, because the artists were relying more on a look or an expression to convey information.

“While previous-generation games did a lot with their character animation and dialog, this next-generation approach will achieve unprecedented subtlety of expression and nuance of performance,” says Blackman. “Now a single look can speak volumes.” For example, Cully Fredericksen as General Kota was the first actor cast. When he came in to read, you instantly felt how imposing he was, just from his sheer physicality, something that his head shots didn’t quite convey, recalls Blackman. In casting Juno Eclipse, LucasArts interviewed many actors who, unfortunately, lacked the “Imperial officer” attitude and personality they were searching for. Unconsciously, the group began making concessions and changing its original vision of Juno until they met Cox, who, coincidentally, looked uncannily like the concept art.

The quality of the facial capture in The Force Unleashed is early testament to the symbiotic relationship ILM and LucasArts are forging at the Presidio campus. LucasArts has already revolutionized ILM’s previs technology and is now at the forefront of performance-capture innovations due to the experience and insights ILM gained on such films as Pirates of the Caribbean: Dead Man’s Chest. “Likeness capture gathers the contours and textures of a performer’s face for the creation of a digital model. The mocap data can then be used to animate that model. The fundamental difference is we’re running the animations in real time, within the game engine, often at 30 or 60 frames per second, rather than the lengthy film-resolution renders that ILM must handle,” says Blackman.

In addition to character models and facial-capture technology, LucasArts was also able to borrow ILM’s effects animation assets—both sound and visuals—to help re-create the blaster bolts of an E-11 stormtrooper blaster or the unmistakable glow and motion-blurred trails and after-images left by the lightsabers as they hum and whine—things that were previously impossible before the processing power of the Xbox 360 and the PlayStation 3. –Martin McEachern

Though Euphoria is used to drive non-human characters in the game, such as the Rancor, it’s yet to be fully deployed for non-bipedal characters. LucasArts has its own engine-side solutions for cloth and jiggling, though it used DMM for parts of the Sarlacc pit, which the player will encounter on Felucia. For animating the long, flowing robes of the apprentice Vader and other similarly garbed characters, the artists employed keyframe animation and, more often, its own in-house cloth-sim technology to drive the robes in-engine. When the game engine is in control of the cloth elements, it allows for wind, momentum, or other forces.

For facial animation, LucasArts still uses bones and blendshapes, triggering facial reactions concurrently, but independently, of Euphoria. While animators keyed some of the facial animation, the majority of the facial performances, for the cut-scenes in particular, were culled from extensive and revolutionary motion-capture sessions conducted at ILM (see “Key Collaboration,” this page). 

The Future
The integration of DMM and Euphoria into the game-development process is strengthening the collaborative relationship between character TDs, animators, and engineers, breaking down the usual compartmentalization of the production pipeline. Enfolding these two cutting-edge technologies into games demands a stable bridge between the content artists and the engineers, says Blackman. While the animators envision the incredible scenarios and breathtaking worlds to be explored in next-gen gameplay, the latter is knee-deep in code. Animators now work far more closely with Euphoria engineers to develop behaviors.

“The size of our animation staff hasn’t changed much,” says Blackman. “But, instead of wasting time animating the 10th variation of a punch or a fall, the animators are now able to focus on character performances and signature animations, such as attacks. So, we have the best of both worlds: endless variation supplied by Euphoria, and handcrafted and memorable animations where they are needed most.”

By the same token, just as animators work closely with Euphoria engineers to develop performances, so, too, do the art TDs work hand in glove with the DMM engineers to bring the environments to life. “They’re the glue that holds everything together. On one side of the spectrum you might have an artist say, ‘I want to have a slug-like creature imbued with DMM so that it is slick and slippery on one end and really sticky on the bottom.’ An art TD would be able to crack and solve that request by working with the engineer to serve up a workflow and pipeline to the artist, so he or she can create that experience in the game,” explains Blackman.

The collaboration between ILM and LucasArts is also breaking down the barriers between film and game artists. “We actively collaborated with ILM to co-develop tools that we used to create Star Wars: The Force Unleashed, and in the realm of visual effects is where LucasArts will benefit quite a bit from this collaboration,” says assistant producer Brett Rector. “What it will hopefully amount to in the end is a palpable ambience in which the audience can become immersed.”


DMM and Euphoria helped the game animators create the compelling action in this scene. However, the artists are quick to point out that traditional animation, including keyframing and motion capture, are still vital to the equation.


While Blackman insists mocapped and keyframed animation will continue to thrive in this new era of gaming, he forecasts the demise of ragdoll animation. “Ragdolls typically look like sacks of flour tied together. They flop around when knocked over or thrown; Euphoria-enabled characters protect their heads, roll with punches, and try to brace themselves when falling. You’ll never see a falling ragdoll character grab for another character or object in the world.”

Player reaction to early builds of the game signaled a radical mind shift in the way we engage interactive worlds, one so enticing it may lure a previously untapped demographic not particularly inclined to playing video games. Astonishingly, many viewers of Euphoria-enabled characters react with empathy for digital people engaged in an independent pursuit of their own self-preservation, infusing the gameplay with an emotional power never felt before.

Indeed, many leading game writers believe that the pivotal plot turns in a game must happen during the gameplay itself, not watched passively in a cinematic. Euphoria and DMM can provide the gameplay with the emotional force to make such interactive storytelling possible. In a recent interview, Prince of Persia screenwriter Jordan Mechner contended that cut-scenes were actually an impediment to the evolution of the medium. He stated: “In a movie, the story is what the characters do. In a game, the story is what the player does. The actions that count are the player’s. Better game storytelling doesn’t mean producing higher-quality cinematic cut-scenes; it means constructing the game so that the most powerful and exciting moments of the story occur not in the cut-scenes, but during the gameplay. The key moments, emotional high and lows, [and] surprising twists of a video-game story are ‘played,’ not ‘watched.’ If the [objective] is ‘Shoot every spaceship you see,’ packing the cinematic cut-scenes full of human relationships, dialog, and backstory won’t deepen the experience.”

As a company uniquely positioned between the cinematic and gaming worlds, LucasArts may be the last to abandon its cinematic tendencies, but right now, it is undoubtedly the first to make the player’s actions count for far more than ever before. 

Martin McEachern is an award-winning writer and contributing editor for Computer Graphics World. He can be reached at MartinMcEachern@hotmail.com .
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