Legos Come to Life

Designing a set of the popular building blocks for both the real and virtual world

By Karen Moltenbrey

The Lego Group used the best of two worlds when it designed the new Lego Rock Raiders game as both a physical toy and a 3D game for the PC and Sony PlayStation. "For the first time in Lego history, children can play with the toy and then hop on the computer and play within the same Lego universe there," says Tomas Gillo, head of concept development at Lego Media International, the company's software division. "We hope that what they see and experience in the CG version will in spire them to go off and build and play with the toy, and vice versa."

While this project was not the company's initial foray into the CG realm, it marks the first time that a Lego play set and computer game were developed concurrently. As a result, the project represents a landmark in Lego's 60-year history in that the development of the play materials was affected by digital-content development.

Rock Raiders, the first Lego game developed concurrently as a play set and a computer game, challenged designers to create a universe for both environments.

A team of 12 animators at Artworld UK, a Birmingham, UK, animation facility, created the majority of the 3D game elements using NewTek's (San Antonio, TX) Light Wave 3D and a variety of third-party plug-ins running on high-end Windows NT workstations. The models were then loaded directly from LightWave into a proprietary game engine from Lego.

For texturing the objects, the group used Adobe Systems' (San Jose, CA) Photo shop and MetaCreations' (Carpinteria, CA) Kai's Power Tools. According to Gillo, the artists had to translate the highly familiar physical Lego blocks, with their recognizable nubs and indentations, into CG while maintaining their look and feel. "Lego is extremely particular about how its bricks are rendered in a computer game," he notes.

To ensure that the colors of the pieces were the same in both the physical and virtual versions, the animators preprogrammed all the correct Rock Raiders colors into a database, which a set of Artworld proprietary plug-ins accessed to automatically paint material values onto blank bricks as they were imported into the program. When completed, a plug-in then generated a scene file with all the cor rect pieces, allowing the artists to assemble the models as they would if the bricks were physically in their hands. "Not only was this fast, but it was ex tremely accurate," says Rob Dorney, head of art at Artworld.

To conserve memory, artists used special lighting and shadowing techniques to make models with fewer polygons look more detailed.

But creating each play piece as a highly detailed model containing thousands of poly gons that would still run on Lego's real-time game posed some problems, "requiring the artists to be extremely clever in their use of textures." This meant making lower polygonal renditions of the characters and objects appear more detailed and textured than they sometimes were by adding reflections, shadows, and other lighting effects. Even so, the PC game still requires a 3D accelerator card.

One of the biggest challenges to creating the digital content, according to Dorney, was giving life to what are typically inanimate objects. "Children like to make up little stories whenever they use the toy set, but in the PC game, the story and the characters come alive," he says. Animating the blocks was no easy feat, however, con sidering that the artists had to simulate the stiff tactile Lego mini figures. But with Lego Media's blessing, the animators achieved their goal by deviating from a few basic but well-established Lego toy design rules.

First they were permitted to make characters whose knee and elbow joints would bend, and whose torsos would twist. "Ima gine having to produce an animation se quence where a character's torso doesn't move; it would have to turn and face everything it looked at," notes Dorney. "Although Lego didn't want us to make these infractions, the company realized they were essential for realistic character movement in the game."

The group also animated the characters' facial textures, "to give each a distinctive personality, even though they are, in effect, plastic figures," Dorney adds. For instance, Sparks the engineer is somewhat silly and clumsy, characteristics that are carried throughout the game in the way he walks (or rather, stumbles) and in his facial expressions.

To maintain the traditional look of the Lego blocks in the CG game required extensive model texturing. As a result, a 3D accelerator card is required for game play.

Further design problems resulted from the parallel game development. "During the early part of the design process, we'd get storyboards and test models from Lego, and we'd see if they were appropriate for what we wanted to do in the game. If they didn't seem to be working out, we'd make suggestions, and they'd try again," explains Dorney. But often both groups would not receive a finalized model design until late in the cycle. "The overall design process took longer than usual [about 18 months] because we had to change and rejig things on our end to fit the model range, as did [the toy de signers]," Dorney adds.

To alleviate some of those pressures, Art world programmers wrote a plug-in for Light Wave that simplified scenes containing all the elements needed to make a particular model by providing the artists with a visual reference whenever they as sembled the final scenes. The group physically broke up the plastic models and built every component in LightWave, inserting each piece into the database plug-in as they were completed. When the artists needed to construct a scene file containing the component bricks, all they had to do was locate the pre-built piece from the database and choose the desired color. Once all the pieces were selected, the plug-in automatically generated the scene containing those pieces.

While the design intent of Rock Raiders was to develop a single environment for two different media, logistically, the play is not seamless.

The tactile toy was limited by the number of blocks (and hence, vehicles and the like) that could be used in constructing objects, while the CG version had the luxury of going beyond the play materials in terms of the number of characters, buildings, environments, and vehicles, in addition to character development. "The toy provided a strong starting point for us, but there weren't enough buildings and such to enable an interesting gaming experience," says Gillo. "We had to create a much larger universe for the digital characters."

This was especially crucial in a strategy game such as Rock Raiders, where the success of a character depends on choices made during game play. In Rock Raid ers, which is targeted at young children, players must accumulate re sources-such as ore and rock crys tals-from the alien planet on which they have crash-landed, so they can eventually get back home. While digging, they must ward off alien monsters, which rely on the crystals as their food source.

According to Gillo, the original game design contained more emphasis on problem solving, including one scenario where the player strategically breaks through rock and uses water for curbing lava flow. How ever, the computational memory needed to accurately calculate the water volume for dispersion throughout the game levels slowed the game play drastically. "If we used this bit, we wanted the dispersion to be accurate, but it just ate up too much CPU time," he notes.

Programmers at Artworld created proprietary plug-ins for LightWave that helped the animators match the color scheme in the digital game with that used for the tactile toy.

With the success of this parallel physical and digital project, Gillo expects that Lego will continue along this dual-offering course. But does this mean that digital versions will soon replace the standard Lego toys? It's not likely. "Children still enjoy playing with the tactile toy," he explains. "We're just providing a greater depth-of-play experience."

Key Tool LightWave, NewTek (www.newtek.com)