By Martin McEachern
When computer game players step up to the plate this year, they will encounter a digital baseball diamond that's been given a radical face-lift. Gone are the generic cookie-cutter players that dominated past baseball titles such as Electronic Arts' (EA) early versions of Triple Play, as lifelike digital replicas of the various teams take to the virtual fields. The new rosters are forming as a result of a joint venture between the Major League Baseball Properties (MLBP) and the Major League Baseball Player's Association (MLBPA) to digitally scan the heads and faces of nearly 900 players and managers, who will eventually appear in titles from such heavy hitters as EA, Sony, Acclaim, and Sega.
The developers, eager to exploit the increased processing power of the current and next-generation game consoles, entered into discussions with the league approximately two years ago about acquiring high-resolution head and face models of all the Major League players for their respective games.
The proposal was en thusiastically embraced by John Olshan, category director of Interactive Games for the MLBPA, who oversees the licensing of the players to game developers. Given the advancements in both 3D scanning technology and the processing power of modern game consoles, Olshan was disappointed that only a handful of recognizable player models were presented in computer games featuring models of real-life athletes. Thus, he seized the opportunity to help licensees raise the bar for player imagery in sports games, vowing to bring gamers "real-time, lifelike, movie-quality, 3D renderings" of every player in the Major Leagues.
This ambitious undertaking has benefits for those both on and off the field. For game developers, using recognizable models of every player with whom fans already identify provides an invaluable marketing tool. For the actual ballplayers, the realistic models will greatly increase their own visibility as well as that of the league.
|The Major League Player's Association and Major League Baseball Properties teamed up to acquire 3D head shots of nearly 900 players and managers, such as Alex Rodriguez, Bernie Williams, Derek Jeter, Lance Berkman, and Pedro Martinez for a line-up of |
The Digital Draft
The scanning project is considered a milestone in computer game graphics, marking the first time that every member of a professional sports league has been digitized for a title or group of titles. For the required technology and expertise, the MLBP, MLBPA, and the individual li censees turned to InSpeck, a Mon treal-based provider of halogen light-based, color, optical 3D digitizers specifically designed for scanning free-form objects and the human form. For example, InSpeck's proprietary technology was used to generate digital versions of the principal actors in the feature film X-Men.
The entire scanning phase had to be accomplished in just over a week-during last year's spring training picture days-to minimize any disruption to the teams' scheduled activities. Before that could happen, though, a consensus had to be reached concerning the data specifications to ensure the models would be delivered in a format that would be most compatible with each developer's unique production pipeline, since all the game li censees would receive the same head data from the league. To that end, they agreed that InSpeck would deliver to the league 3D polygonal head meshes of all the players and managers at a maximum density of 80,000 polygons, with a UV texture map resolution of 2048 by 1024 pixels.
|With the new processing capabilities of game consoles, new and upcoming titles such as EA's Triple Play 2002 will feature lifelike digital replicas of various players and their respective ballparks. |
Once the logistics were worked out, In Speck dispatched three crews to the league's spring training facilities in Florida and two to Arizona, each traveling to a different stadium every day to scan a specific team using the 3D Capturor digitizer. Classified as a structured light scanner, the 3D Cap turor projects a halogen light pattern onto a player's face, then uses a camera to record the distortion of the pattern caused by the contours of the face, which the control software interprets to triangulate 3D coordinates. During a two-minute period, each player, seated on a rotating stool, was turned 360 degrees while the 3D Capturor acquired one shot every 45 degrees, as well as one of the top of the head. Captured with a lateral resolution of 0.6mm and a depth resolution of 0.5mm, the geometric data was saved as a polygonal mesh along with simultaneously captured UV-mapped texture information, ensuring a perfect fit between the surface and the texture.
After the scanning was completed, the five crews returned to Montreal with a plethora of CD-ROMs containing the nine partial views of 874 individual Major League players and managers. The views were then merged to form a completed 3D head model in InSpeck's EM surfacing software. However, merging the textures into a projection map that could be easily wrapped around the model was no easy task. "The typical cylindrical texture projection has serious limitations when used on a head, since it cannot generate texture on the top of the head," explains Marco Estrela, marketing and channels manager for InSpeck.
|Using its 3D Capturor digitizer, InSpeck captured partial head views of each player (left column), illustrated here by images of Luis Gonzalez. The data was then consolidated using InSpeck's EM surfacing software (middle column) to form the completed |
"The other frequently used form of texture projection is cubic projection. But when loaded into a 2D texture editor, it looks like there are a thousand pieces." Hence, the traditional cubic and cylindrical merging techniques used by InSpeck in the past failed to produce complete and easily customizable textures, which the game developers needed for preparing hundreds of heads at multiple resolution levels for their games. To overcome this problem and outfit the companies with more workable maps, InSpeck developed an innovative hybrid between spherical and cylindrical projection maps, which could be readily edited within a 2D texture editor and applied to the head.
One of the first games to showcase the new head models is this year's edition of EA's Triple Play for Microsoft's Xbox and Sony's PlayStation 2 consoles. After refining the scanned geometry and texture to EA's specifications, InSpeck delivered the data to the developer's Redwood City, California, facility, at which time Alessandro Tento, senior art director for EA's Triple Play 2002, and his team of artists and programmers had several months before the game's release date to get the players game-ready. This work included further refining the geometry and textures; stitching each head to a scalable, ready-made body; completing a host of facial and body animations that included both the signature batting and pitching styles of the players and the motion-captured movements of the game's spokesman, Luis Gonzalez; and developing a totally new game engine that would serve as the prototype for future editions of the title.
According to Tento, the artists and programmers had two particularly large challenges to overcome before they could integrate the digital heads into the game. First, they had to reduce the file sizes of the individual heads, which were too large for the memory capacity of either the Xbox or PS2. Second, they had to develop a game engine that could coordinate the unprecedented number of art assets that would be swapped in and out during game play.
|InSpeck combined spherical and cubic projection maps to apply a 2048 by 2048 texture map to the various head models, as illustrated in this image of Luis Gonzalez. |
Because of time constraints, the artists were able to use only 170 of the 3D heads for the 2002 release. For the virtual players who did not make the cut, EA created 15 generic heads, comprising all ethnic groups present in Major League Baseball. This was done by mixing different facial features culled from a variety of photographic resources and portraits the group took with a digital camera.
For preparing, rigging, and animating the geometry of a player's face, body, and fully articulated hands, EA used Alias|Wavefront's Maya. To simplify the importation of the head data, EA scripted proprietary tools and exporters that reduced the density of the meshes without compromising the distinctive facial features of each player.
Nevertheless, the artists spent hundreds of hours working in Maya to further tailor each head for four different levels of detail (LOD), which varied in geometric density from 500 to 4000 polygons. One of the four versions could then be selected according to the player's distance from the viewer or the complexity of a given scene to accelerate the drawing of each frame.
"In the highest LOD, the polygons matched the morphology of the player's face, but for the lower levels, the head geometry was just a generic head model," explains Tento. "Because of model distance, the extra detail would be lost anyway. However, we retained [lower resolution] textures for each player's face in all of the LOD models, which enabled us to minimize any visible switching between the different levels."
|To incorporate the heads of players such as Luis Gonzalez into its game, EA's artists reduced the polygon count of the geometry from 80,000 to 4000 for the highest level of detail, and scaled the texture map to 128 by 128 pixels. |
Once the modelers rebuilt the players' heads for the game, they aligned the vertices at the base of each head with the adjoining vertices of each body, making sure they were identically weighted. This way, the degree of influence exerted on both by the underlying skeleton was equal and the two pieces would deform as one. Because of the abbreviated production cycle, though, the group created only one body model for all the characters in this year's edition of the game.
Through a series of programs, the shape of the model was automatically modified in real time according to database entries for each player's height, weight, and build. The player's body was generated with quads, or four-sided polygons, to optimize the display frame rate and the rendering speed, and was surfaced by lead modeler Min Choi to withstand the extreme range of upper-body movement displayed in baseball without twisting abruptly or unnaturally. In particular, the animation of the upper torso demanded an evenly subdivided polygonal mesh that would bind smoothly to the skeleton and, therefore, deform realistically across all the extreme motions.
According to Tento, the player skeleton was kept fairly basic to constrain animation file sizes and to simplify the workflow of the animators. "In a baseball game, you have to deal with a vast number of animations that include stances, signature moves, and scripted sequences," he notes. "If we set up a skeleton with too many bones, the resulting data fed into the game would inevitably be far too big to fit into memory."
|Using Maya's Set Driven Keys, animators controlled the players' hand and body positions to mimic 30 individual batting stances. |
Though EA's artists used forward and inverse kinematics (IK) for most body animation, the skeleton's hand comprised too many joints to be animated by simple keyframing of the bones or IK handles. Alternatively, the team employed Maya's Set Driven Keys for the hand animation, through which all the motion of the bones and IK handles in a particular hand movement was "driven" by a single slider-controlled tool.
For example, to accomplish the bat-gripping action that occurs as a batter takes his stance at the plate, the team used a Set Driven Key, with the beginning and end of the hand movement defined by a value range between 0 and 1. That value could then be adjusted with a slider to position the hand into any shape the animators desired. At position 0, the hand was in a relaxed state; at position 0.5, the hand was set in a semi-open posture; and at position 1, the hand was clenched around the bat. Therefore, instead of repeatedly keyframing all 24 bones in the hand each time the gripping motion was required, animators only had to move and key the slider. Approximately seven different hand movements were created as Set Driven Keys, resulting in a variety of animations, including high-fiving, fist pumping, and bat-gripping actions for 30 authentic batting stances.
The group also developed facial animations to make the new players appear more demonstrative and engaging. Instead of repeatedly keyframing clusters of control vertices or using morph targets, animators Matt Derksen and Brian Robinson developed 23 Set Driven Keys for manipulating the eyelids, eyebrows, jaw, cheeks, and mouth into a wide range of facial expressions, including grinning, frowning, and smirking.
Next, InSpeck's original 2048 by 1024 texture maps were fine-tuned in Adobe Systems' Photoshop so they could be seamlessly overlaid with the neck textures of the players. The textures were scaled down to a resolution of 128 by 128 pixels for the highest LOD and mapped onto the head using bioVirtual's 3DmeNow software. Although time constraints demanded that the player-model's art assets be as sharable as possible between the Xbox and PS2 versions of the game, EA exploited the Xbox's greater capacity for texture detail by dedicating a separate texture pipeline for the Xbox player faces, whose resolution is roughly double that of their PS2 counterparts. However, for the Xbox version, the artists were limited to using the higher resolution textures for only a small selection of star players.
|To coordinate each player's body and head assets during game play, EA's code accesses a database of measurements for each person. |
"We plan to extend the same treatment to all the player models for the [Xbox version], possibly enhancing the texture detail and pushing the technical limits even further," Tento says. "Although each head has distinctive geometric fea tures, the [highly de tail] textures allow us to enhance the realism to an even greater extent."
Another major in con sistency between the Xbox and the PS2 emerged during the lighting of the player models and the 30 meticulously re-created Major League parks. Both versions use the same game engine, so the artists had to compensate for the subtle differences in the way color registers on each console. Under the same lighting, tex ture intensity, and saturation values, the Xbox version looked desaturated and lacked visual punch due, in part, to the system's robust antialiasing filters. To compensate for this disparity, the saturation and contrast values of the Xbox textures were raised by approximately 30 percent to replicate the look of the PS2 edition-a more effective alternative than changing the lighting for each platform.
|Ichiro Suzuki displays the enhanced facial expressivity EA developed to control facial features such as the eyelids and cheeks. |
"As much as we could, we separated some common assets to accommodate the increased detail afforded by the Xbox," explains Tento. "In other instances, we had to compromise, finding a sweet spot for color and intensity values that averaged the differences between the two platforms."
Furthermore, by faithfully translating the look of each texture to the Xbox, the artists not only retained the newfound realism in the players, but also preserved the unique atmosphere and character of the stadiums. This was accomplished by senior artist Yves Couturier, who translated details from myriad photographs to hundreds of distinct textures that were subsequently color corrected to evoke different times of the day and a variety of weather conditions. Using Discreet's 3ds max, Couturier built each stadium within a top-end polygon count of approximately 12,000, and referenced actual blueprints to ensure the proportions and cross-sections were made to scale.
Finally, Triple Play's programmers developed the necessary code to coordinate the extraordinary number of player assets used during game play. When loading a star player's head into the game, the code first accesses a generic "base" head. The topology of a scanned player's head is then generated by applying the x, y, and z displacement of its vertices from the base head. Meanwhile, the code scales the body model in real time according to the database entries for the model's weight, height, and build, then stitches it to the head. "After that, it becomes a database maintenance task to track all the head assets and have them show up in the game, placed on the correct player's body," says producer Brent Nielson.
As the newly scanned players enter their rookie season this year in titles from Sony, Sega, Acclaim, and EA, the Triple Play crew is actively preparing a host of improvements for future editions. This includes a game engine that will use several body types to more accurately represent the actual players and even more detailed texture maps for all the players. The group also plans to incorporate a greater number of the 874 heads that were already digitized.
In the meantime, EA's Triple Play 2002 represents a turning point in sports gaming graphics, instilling in the fans an expectation that every player model be a recognizable 3D rendering of its real-life counterpart. It's also forcing developers to embrace scanning technology that was prohibited by the hardware limitations of the older consoles. Now, with those barriers broken by the Xbox, PS2, and Nintendo's GameCube, 3D scanning technology is stepping out of the CAD and engineering markets to become a major player in the gaming industry.
"3D scanning is definitely here to stay," affirms EA's Tento. "Electronic Arts is exploiting the technology across many current and future sports titles to deliver an unprecedented interactive experience. Visual realism and sports games go hand in hand, driving the need for new levels of graphic sophistication." Moreover, with EA's current lineup of sports titles covering hockey, soccer, basketball, golf, football, boxing, motor sports, and even cricket and rugby, the potential transformation awaiting the industry is vast.
|The player skeleton was kept fairly basic, allowing animators to create a number of signature moves for players like Bernie Williams (top) and Greg Maddux (bottom).|
Not surprisingly, InSpeck's Estrela is equally excited about the budding market for its technology. "We believe that the new games featuring these highly realistic 3D heads will become so accepted by the gaming community that a new standard will be established for all other games," he says. And InSpeck may not be too far away from upping the ante even further by delivering a higher degree of realism though its 3D Full Body digitizer, which perhaps prefigures the next stage in the graphical evolution of sports games.
For now, it's Major League Baseball that currently finds itself on the vanguard of a movement that could eventually see sports and entertainment personalities brought en masse into the world of computer gaming. In fact, as part of its agreement with the league and the licensees, InSpeck will digitize new players on an annual basis, making its scanning crews a fixture at spring training. Posing for a 3D photograph will become a new rite in every Major League Baseball player's career, while the new breed of games, apart from yielding a richer interactive experience, emerge as time capsules of virtual memorabilia.
Martin McEachern is a writer and digital artist living in Toronto. He can be reached at firstname.lastname@example.org.
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