Fighting games have always been a popular choice for video game enthusiasts. When battling invading aliens or mutant vampires just isn’t visceral enough, there’s nothing like taking on another simulated human being in a little boxing or acrobatic hand-to-hand combat. When the team at EA Tiburon⎯the Orlando, Florida−based video game development studio for Electronic Arts (EA)⎯decided to create a game depicting the gritty sport now known as mixed martial arts (MMA), however, they were determined to make it unique.
Crucial to creating the stunning realism of many EA SPORTS games is ANT, a proprietary middleware solution created by EA and used to create such popular sports titles as Fight Night and NBA JAM. Autodesk® HumanIK® middleware has been an integral part of ANT from the beginning of its development. Together with Autodesk® Maya® and Autodesk® MotionBuilder® software, EA Tiburon made extensive use of HumanIK middleware to help create what EA Tiburon considers to be the most realistic fighting game ever with EA SPORTS MMA.
The sport of MMA⎯also known as ultimate fighting, no holds barred, or cage fighting⎯combines techniques from boxing, martial arts, and traditional wrestling into an extremely demanding competition. Competitors can kick, punch, tackle, grapple, and wrestle in any combination, while protecting themselves from the same techniques. The unpredictable nature of the sport presents some obviously complex challenges to a video game developer. Characters need to be very believable in nearly every way.
“From the start, creating completely realistic human fighters was our top priority,” says Kevin Noone, computer graphics supervisor, of EA Tiburon. “In the past, fighting games have tended to be more about mashing a lot of buttons than simulating a real fight. For EA SPORTS MMA, not only would the skin, hair, sweat, and blood of the fighters need to look absolutely real, but the contact and overall interaction of the fighters would be a fully accurate simulation.”
“We had already done some groundbreaking work with games like Fight Night, but EA SPORTS MMA promised to be an entirely different animal,” says Simon Sherr, animation director at EA Tiburon. “MMA is an anything-goes style of fighting, much more fluid and unpredictable. From a design standpoint, we set out to create a peer simulation fighting game giving the players absolute control. We took punch control and went way, way beyond.”
Sherr isn’t exaggerating. While the punching and kicking provide at times bone-chilling realism, it is the visceral sense of complete and consistent contact that makes EA SPORTS MMA utterly compelling and unique among fighting games. Fighters move independently from one another, but react to one another’s movements in strikingly realistic ways. Myriad muscles twitch and flex into action and ripple and undulate when hit. Even the fighters’ own blood will smear on to his opponent in the midst of the close-quarters grappling that typifies mixed martial arts.
Making it Real with Autodesk Maya and Autodesk MotionBuilder
“With Autodesk Maya software and integrated mental ray rendering, we were able to previsualize the most realistic fighters,” explains Noone. “We were then able to use the renders as a visual target with the graphics engineers. This enabled us to create the best possible humans in real time.”
The EA Tiburon team used Autodesk Maya both for previsualization and to help create precise modeling of all the fighters. The motion capture and animation capabilities of Autodesk MotionBuilder software were used to create kicking, punching, and grappling moves so realistic game players will feel their own muscles aching with fatigue.
“We have an excellent pipeline using Autodesk MotionBuilder for animation,” says Sherr. “Autodesk MotionBuilder is simply a brilliant animation tool. Using another package at this point would be like taking my hands away.”
Making it Believable with Autodesk HumanIK
So, how do you get computer-generated characters to anticipate and react like finely tuned fighters? Among several programs created by the EA Tiburon team using Autodesk HumanIK are what they call “attitudes,” a technique based on what the EA team calls procedural awareness, which was in turn developed for EA SPORTS legendary FIFA Soccer franchise.
Sherr explains: “We wanted to eliminate that dead cow stare that is typical of most fighting games. Using procedural awareness, we can give our characters a lot more personality. With what we like to call ‘eyeball tracking,’ we can fine-tune how each body will react to a specified target in space as the eye follows it. HumanIK was crucial to the increased believability of those movements.”
The EA Tiburon team also made extensive use of HumanIK to help develop realistic foot pinning, to determine more precisely where and how each fighter’s foot will be planted for a particular move. Touch tags enable more believable punching and kicking motions by specifying multiple targets in space, each of which is relative to the fight animation.
Grappling presented a particularly complex challenge in EA SPORTS MMA. Sherr and his team needed to employ nonuniform player scaling, which involves appropriately changing the length of a character’s limbs and joints to convey different body sizes and proportions.
“Player scaling was very important to the realism of the game, and we could not have done it so well without Autodesk HumanIK,” says Sherr. “We needed the middleware’s full-body inverse kinematics to get the effect we were after. When you need to create the sort of extremely precise character interaction we have in EA SPORTS MMA, there is nothing remotely close to Autodesk HumanIK middleware. Fight scenarios that would have given me nightmares before are now ready to go in a fraction of the time. I could not imagine doing that with any other tool.”
Also crucial to believable fighting, and particularly close wrestling and grappling, is an EA technique Sherr calls “Relative IK,” which uses a combination of HumanIK and MotionBuilder to help create very complex relationships between the virtual combatants.
“Once we’ve developed a polished, two-man animation, we create all of the important contact relationships between the fighters,” says Sherr. The fact that HumanIK middleware is integrated into both ANT and MotionBuilder is a huge plus for us, because the interoperability is essentially seamless. I can go into MotionBuilder and add auxiliary effectors on one fighter and parent them to his opponent. For instance, if I’m grabbing him by the head, twisting his arm, rolling him over, I can create auxiliary effectors for each of those contacts, all of which makes transitioning between those positions more realistic. Those auxiliary effectors are then exported with the animation, along with each effector’s location relative to the joint to which it is parented. Needless to say, it is a complex process, but the combination of HumanIK and MotionBuilder makes it much easier.”
The EA Tiburon team accomplished this using MotionBuilder and HumanIK quaternion evaluations to specify rotations around an arbitrary axis, thereby achieving smoother animation interpolations.
Sherr is justifiably proud of the finished results: “I’ve never worked on a game where we have been able to apply this level of polish. With the right tools and the right team, EA SPORTS MMA has unsurpassed levels of fluidity, quality of motion, control response, and so many other elements. And the fact that the game is entirely data driven means we have an excellent architecture for expansion. Thanks to the work we’ve done on ANT, EA SPORTS MMA was much easier to create and enhance than it would have been. And, in turn, the next version will be much easier to build and enhance.”
EA Tiburon also got some help from Autodesk® Consulting to extend the viewport in Autodesk Maya and provide real-time rendering for EA SPORTS MMA and future EA games:
“Autodesk Consulting helped us open up the Maya viewport, and provide the team with tools to connect re-rendered visualizations with the viewport,” says Sherr. “The viewport was eventually rendering in real time. The tools are now being used in games currently under development.”
Whatever else, one thing is certain: with a little help from Autodesk software, EA Tiburon has given gamers the most realistic fighting experience most of us will ever have outside of an eight-sided ring.