Issue: Volume: 24 Issue: 5 (May 2001)

One for the Ages

The otherworldly images in Myst III: Exile, the long-awaited continuation of the legendary Myst computer game series, are the kind that dreams are made of. In fact, Exile's mysterious worlds, with their strange flowering plants, hybrid animals, azure waters, and Camelot-like architecture were supposedly created from the thoughts and dreams of the game's main character. Yet the detailed texturing of the 3D imagery, the seamlessly composited video footage of live actors into scenes, and a new 360-degree panning technology blur the line between the surreal world of the game and the real world of the player. · Utilizing the technological advances that have occurred in 3D hardware and software over the past five years, the animators at Presto Studios have constructed five distinct universes, or "Ages," in Exile that transcend the realism of the previous Myst installments. · Tomahna sits like a garden oasis at the edge of an endless desert landscape. J'nanin, an elliptical-shaped island, is home to towering granite cliffs and strange, tusk-like formations that surround an azure caldera. Voltaic, a dusty world of sand and sky, water and wind, contains strange, man-made constructions that inhabit an otherwise dry and desolate landscape. Amateria, a mechanical wonderland in the middle of an endless black sea, consists of basalt columns and geyser-formed mud pots that poke through the landscape amid sophisticated mechanical inventions. And Edanna, possibly inspired by dreams of paradise lost, is contained in an inward-growing tree whose massive, hollow trunk creates the perfect environment for a variety of exotic plant and animal ecosystems.

Cyan raised the bar for graphics realism in gaming when it released Myst in 1993 and its sequel Riven in 1997. With Cyan committed to other projects, Presto Studios was chosen to continue the Myst tradition of artistic beauty and striking imagery, the likes of which have never been seen before.

The most challenging modeling task, ac cording to lead animator Mike Brown, was creating the Ages, or islands, which are the focal point of the game. This is in contrast to most computer games, in which the characters and action -rather than the landscapes-are the main attraction. As a result, the imagery, which is all pre-rendered 3D, had to be especially compelling to capture and hold players' attention.
Using 3D Studio Max, Presto Studios created five diverse landscapes for the computer game Myst III: Exile. One of the more intriguing game worlds is J'nanin (center image), an island filled with unusual rock formations that captivate players with thei

One of the most compelling Exile Ages is J'nanin, described by Brown as "a rock climber's paradise." To ensure that J'nanin, as well as the other Exile Ages, retained a unique graphical appearance, each was assigned its own designer and production team, while creative director Phil Saunders worked to maintain an aesthetic consistency among them. Conceptual artists decided how each island would look, and then 3D artists formed the various terrains using Discreet's 3D Studio Max. To create J'nanin's environment, Brown first built a simple representation of the entire Age by lofting shapes, a process of creating shapes or cross sections of a model and then letting the computer extrude those shapes to create 3D structures.

To smooth the terrain's surfaces and add the more detailed geometry, he subdivided the surfaces using 3D Studio Max's Meshsmooth. "Organic surfaces like wood and rock are extremely complex to build in 3D environments, and it would have been impossible to model all the subtle undulations, cracks, and crevices in J'nanin's landscape," he says. Instead, the animator painted them into the surface using displacement maps. "For J'nanin, I created nearly 100 custom displacement maps just to build the terrain."
To build J'nanin's cliffs, artists extruded simple shapes into more complicated geometry (right). Subdivision surfaces were then added for a more polished look (below).

For the shaders, which add textures and colors to the geometry, Brown created a single, smart shader that could be applied to all the terrain in the Age. "Because J'nanin is such a large environment, if I tried to create a custom shader for each piece of the terrain, it would have taken forever to finish," he explains. Alternatively, the smart shader automatically decides where to apply different bitmaps, surface attributes, and procedural textures based on predefined rules that take into account, for instance, the surface's location, slope, elevation, and convex or concave attributes, as well as the amount and direction of sunlight the surface receives. "As a result, we were able to apply the same shader to vast areas of the island without having to worry about tiling or seeing a repeat in the texture," Brown explains.

Lastly, Brown created debris such as dirt and weeds to make the terrain appear more realistic. He also added numerous irregularities to the geometry and textures to give the terrain a more natural feel.

"These are fantasy worlds and, by nature, they have to look unrealistic," maintains artist Keith Self-Ballard. "So the paradox is, how do you take these concepts and models that are truly bizarre and dreamlike, yet give them a realistic quality so the players can actually believe they are in these fantasy worlds?" The artists found the answer by using photorealistic textures to project a sense of familiarity, even if the models-architecture, landscapes, characters-are completely unfamiliar.

To create the vast library of realistic textures that would be used in the game, the texture artists photographed a variety of objects, from the ordinary to the extraordinary. "I've gone all over the San Diego area-from the Renaissance fair to the Del Mar racetrack-to acquire certain textures," says Self-Ballard. "Even if I go hiking, I'll bring a camera and shoot some rock textures or natural environments." Once the images were scanned, some of the surfaces were enhanced or altered with Adobe Systems' Photoshop and Corel's Painter to give them a unique appearance.
The imaginations of the artists grew wild while creating the exotic plant life in the Age of Edanna. A blend of realistic and unusual textures enhances the look of the foliage.

The degree of texture manipulation depends on the complexity of the object and its composition. Other issues were also considered, such as the size of the object, how the player interacts with it, and the proximity of the object to the player. For example, one of the more difficult objects to texture was a gigantic metal wall that's crusty, rusty, and scummy from being close to the water's edge. "It's picking up the surrounding seaweed and algae, and you can see the shadows of the dark rocks near it," Self-Ballard says. "Not only do you see this texture from a good distance away, about 20 to 30 yards, but you are also within 2 feet of it at different points in the game. So it had to have a really defined texture once you got close, and a unique, non-repeating texture from afar." He accomplished this duality by creating a larger texture than he normally would have made and by using Max's Distance Blender feature, a plug-in created by Blur Studios. As a result, even though encountering this imposing structure along the island's rocky seawall might suspend belief, its realistic textures makes the player forget just how unnatural this object really seems.

Another texturing challenge occurred during the creation of the huge variety of botanical elements for one of the game's more organic Ages, Tomahna. Within a massive solarium in this world grow unique plants and flowers created by Derek Becker using Electric Image's Animation System, along with Tree Professional from Onyx Computing, which enabled him to obtain the necessary detail that would result in a realistic look. For the more exotic plant life and to fill out the branches of the large inverted tree in the age of Edanna, Brown created a "cluster of leaves" file with a huge procedural texture. He slightly deformed each leaf texture, giving each of the 82,162 leaves an individual look, and then added noise to the geometry, which in turn gave each leaf its unique shape.
Myst III: Exile introduces players to distinctive Ages, such as Voltaic, an arid, dusty world that is littered with unusual mechanical inventions.

In some instances, however, the team of artists wanted a more alien look for the exotic plants, such as the complex vines that twine through one of the Age's landscapes. "For this Age, I created some of the strangest textures-such as backlit bubble wrap, which I photographed and scanned to create a very interesting pattern for some of the vines," explains Self-Ballard.

One of the more unusual aspects of Exile, and the Myst series in general, is the absence of 3D human game characters, which gives the Ages a mysterious quality. Instead, live-action performances by actors are introduced through video segments, as the characters weave the tale of Exile, which heightens the intrigue. To add suspense in Exile, the developer seamlessly incorporated bluescreen shots of various character "cut-outs" into the 3D game environment using Discreet's Combustion. By using this technique, players may catch a glimpse of a covert villain as he disappears behind a doorway.

In all, the game contains more than 40 minutes of live-action video, filmed at PVR (Pacific Video Resources), the same stage company used for Riven. For editing the video, the group used Combustion.
Continuing in the Myst tradition, artists created Exile devoid of human character models. Instead, the landscapes are inhabited by unusual, hybrid creatures such as the Squee.

Although human models do not inhabit the worlds, there are a number of strange creatures that give life to the landscapes. "This is unusual for a Myst game," notes Brown. "But players can't ignore them; they have to interact with the creatures in order to solve some of the puzzles." One such animal is the Squee, a chipmunk-rabbit hybrid that, surprisingly, does not seem out of place in the Exile world. To create the creature, the artists modeled it in 3D Studio Max and textured it with Digimation's Shag/Hair, a Max plug-in. To complete the believability of the character, Brown visited a local zoo, where he photographed raccoons, rabbits, and chipmunks, and combined their movements to make up those of the Squee. The result is an animal that looks strangely familiar yet somehow different, as its bizarre features seem to fuse into a natural look.

There is a price for such realism, however. Because Exile is a texture- and polygon-heavy game, with a number of procedural effects such as flowing water and pulsing sun flares, it requires a tremendous amount of rendering resources. J'nanin alone contains nearly 5 million polygons, 500mb of textures, and 400mb of shadow buffer, in addition to the raytraced surfaces and water. "If we would've added normal volumetric lights to the mix, there's no way we could've rendered it," says Brown. (For rendering, the group used 34 733mhz dual-Pentium III machines with 1gb of RAM.) As an alternative, the group used a Max lighting plug-in, Bunch of Volumes from Cebas Computer, which enabled the artists to use volumetric lights on a grand scale without bringing the rendering hardware to a standstill.

"Normally, volumetric lights are very processor-intensive and take a long time to render," Brown says. "Because of the size of the files we were rendering, we would not have been able to include volumetric lighting without the plug-in." The Bunch of Volume software creates post effects, collecting all the necessary 3D information, including shadows, during the original Max rendering pass, and then rendering the volume lighting effects on a second pass.

However, that did not solve all the rendering problems. In the J'nanin Age, there were so many objects and textures that the entire scene could not be rendered simultaneously, so it was done in four separate passes. "We got all the raytracing and image quality we wanted. There's great-looking water and plants, and underneath that layer we have really high-end, detailed terrain," explains Brown. "Basically, we pushed everything past the point where it would render, then came back just far enough to get it to work."
Using Cebas's Bunch of Volumes software enabled the artists to add volumetric lighting to the imagery without crippling the rendering process, resulting in this colorful sunset in Amateria.

To illustrate how far these images in Exile have evolved from the previous titles, consider that Cyan's original Myst, created with Strata's StudioPro running on Macintosh Quadras, resided on a single CD-ROM. Although the sequel Riven (created with Softimage running on SGI Indigos) required five CD-ROMS compared to Exile's four, it's not for the lack of highly developed imagery. Rather, Presto was able to fit more raw data on fewer discs thanks in part to RAD Gametools' Bink video-compression technology for the in-game video sequences, which typically provides a compression ratio of 20:1, and sometimes as much as 50:1, without losing graphics quality.

According to Brown, surpassing the quality of the legendary landscapes found in Myst and Riven required the collective talents of a team with backgrounds in industrial design, architecture, drafting, animation, traditional painting, and sculpting, which could push current development tools to their limits and, when necessary, create new ones to achieve the desired effects. All the software ran on a Windows NT platform, though Macintoshes were also used for some of the game design, and the game logic was programmed solely on a Macintosh PowerBook.

The team also developed a host of proprietary tools, including a 360-degree panning technology that enables players to click on an object and interact with it while still continuing to look around the surrounding environment. Landmarks, such as the huge tusk formation protruding from the ground on J'nanin, help players orient themselves in the worlds. "The panning, which allows players to walk smoothly through the universe, makes Exile far more immersive than any of the previous games in the series," says Brown. In those games, players navigated the landscape in an incremental, slideshow fashion, unable to more fully experience the 3D imagery. Exile's audio is presented in a similar way to its panning graphics, so when a player turns toward a sound or navigates closer to it, the sound becomes louder.
The images and landscapes in the Ages of Voltaic (top) and Amateria (bottom), appear so realistic that they could have originated from photographs of actual locations.

The new game is powered by a proprietary engine, called the Sprint Engine, which displays the pre-rendered images using real-time technology and the player's 3D accelerated computer hardware, if present. "Many mainstream gamers do not have hardware acceleration, and we'd be missing a large market by making Exile a real-time only game. Yet we wanted to advance the pre-rendered adventure game genre so that it is competitive in today's market of high-end 3D games," says Brown. "By focusing Sprint's technology to produce high frame rates, high image quality, and compatibility across systems with or without hardware acceleration, we're keeping the system requirements very low to run the game."

After nearly 90,000 work hours, Exile will be released this month to eager fans worldwide. To play the beautiful, rich worlds of Exile, players need a 233mhz Pentium II with an accelerated graphics card (optional), or a 233mhz G3 Mac, also supporting optional 3D hardware acceleration. Without the accelerated hardware, players will miss out on a few of the more advanced features, such as the moving water, sun flares, and increased frame rates, but will still be able to play the game.

Yet all these extra features only further add to the player's immersion in this fantastical universe. While the main character Atrus, according to the story line, is credited with the creation of these Ages, there's no doubt they were made real by the artists at Presto.

Now it's up to players to decide: Is Exile real, or is it just a dream?

Karen Moltenbrey is a senior associate editor of Computer Graphics World.

The Exile saga is a continuation of the Myst story, which centers on "worlds," known as Ages, created by the ancient D'ni culture through a mysterious technique for making so-called "Linking" books that transport readers to these parallel universes.

In the original Myst, players were transported onto a gorgeous uninhabited island without instructions as to how to proceed with the game. Left to their own devices, players would discover that by solving various puzzles, closely examining objects, and watching snippets of video, they could uncover the secrets of the island, the D'ni culture, and a family's betrayal. The action continued in Riven, an Age used by Atrus-a master writer of the Linking books-in an attempt to trap Gehn, his father, who had become dangerously unstable.

Exile, which occurs 10 "story years" later, introduces a new villain, a bitter man whose home world was destroyed by the sons of Atrus and his wife, Catherine, whom players encountered in the original title. The villain has been hiding on one of the Ages created by Atrus, waiting for his chance at revenge. Players must track the villain through five new Ages, navigating puzzles to uncover the truth behind this new adversary and stop him before it's too late. -Karen Moltenbrey

Adobe Systems *
Apple Computer *
Blur Studios *
Cebas Computer *
Corel *
Digimation *
Discreet *
Electric Image *
Onyx *
RAD Gametools *