3D Design - April 99 - From CD to Silverscreen
3D Design - April 99 - From CD to Silverscreen
From CD to Silver Screen
Digital Anvil's popular computer game Wing Commander is winging its way to the big screen. Join us behind the scenes as we look at the transition from desktop to feature film. BY MARSHAL M. ROSENTHAL
This is a "moving" environment in the Enyo sector. The Tiger Claw is entering a pulsar singularity to jump to a different sector. The pulsar effect was created with almost 30 layers of animated go texture maps as well as live action, time-lapse footage of storm clouds. All elements were composited using AliaslWavefront's Composer software. Interactive lights were timed with the lightning flashes in the pulsar's core.
The Diligent heads full force into the Scylla jump gate, which will take it from the Sol sector to Gateway sector. Animated textures and deforming geometry helped bring this effect to life. Notice the interactive lights from Scylla on the Diligent. Very dynamic camera motion and shake were used here to demonstrate the wild forces of being pulled into the Scylla.
Below: a cross-section of the Tiger Claw.
In this early test render of one of the CG Rapiers, actual photos of live-action Rapiers were used as reference to create the texture maps for the CG model.
Two Rapiers and the Diligent begin their attack on the Kilrathi communications ship off in the distance. The Rapiers' thruster effect, one of the many automated effects built into the Rapier model, is apparent here. The animator had to move a slider to get the desired spread and intensity of the thrusters. Also notice the interactive lights and shadows across the Diligent's surface.
Exterior beauty shot of the Tiger Claw. The ship had to match exactly a physical model used for a live-action sequence of the hangar doors.
This before- and -after image presents the Kilrathi communications ship being integrated into its environment. Proper self-illumination, shadowing, and atmosphere help tie the ship into the background.
In this moving, top-down view of a Rapier landing in the runway hanger of the Tiger Claw, the Rapier is CG and the background is live-action. A lot of work went into integrating the ship by matching color, tone, and contrast as well as light and shadow placement. The wide -angle lens used in the live-action shoot also had to be precisely matched.
Perhaps no one should be surprised that Hollywood has found a popular computer game to morph into a movie. But Wing Commander is surprisingly well suited for the big screen, thanks to realistic computer graphic (CG) effects that translate the action from the computer screen to the silver one.
Wing Commander the movie shows a grittier reality than most of today's space warfare films. In his $27 million production, director Chris Roberts' vision of fighting vehicles in the year 2654 is more World War Il epic than Star Wars serial. Roberts (also creator of the Wing Commander game series) presents a future that discards the sleek, designer look of science fiction we are used to seeing in films and replaces it with a vastness filled with quasars, nebulae, brown dwarf stars, planets, moons, asteroid belts, and neutron stars all vying for attention in full detail and color. Wing Commander may be high-tech, but Roberts' universe still comes down to soldiers crowded together in war-torn, battle-scarred ships, fighting their way through hell.
To create this universe requires the computing power of Austin, Texas-based Digital Anvil (www.digitalanvil.com), a company that has both created computer games and produced bleeding edge digital effects for film productions. Digital Anvil began creating Wing Commander's CG effects with animatics and storyboards two months before principal photography began in early 1998. Tom Dadras, Digital Anvil's digital effects supervisor, said that it wasn't just a matter of creating the effects in isolation. These effects ultimately had to be integrated with live-action scenes, including full-size space fighters in battle sequences. The director of photography got involved to ensure that the Kodak film stock used would mesh with the look of the digital effects so that the live and CG action would blend together seamlessly.
Digital Anvil began by using a prerelease version of Alias|Wavefront's Maya computer animation software. According to Dadras, the main advantage of Maya is that it enables digital artists to work more efficiently by making all of the modeling, animation, rendering, and particle effects accessible through one integrated program, which eliminates the need to import/export data from one program to another. (The software was updated to version 1 for most of the production, with 1.5 becoming available during the last month of the production. However, the team didn't switch over to this new version in fear that the frames would change their "look" within a shot.)
Chris Olivia, Anvil's visual effects director, said that Maya also allows for quick feedback from hardware lighting to dynamics, so that the artists didn't have to wait to look at a rendering. (Many of Wing Commander's digital models had a large number of 3D surfaces, which translates into longer rendering times.) Maya was run on 195MHz SGI Octane computers (each with 4GB hard drives and 384MB of RAM), with work viewed on 21" and 24" color monitors capable of the wide screen format/film aspect ratio 1:2.35. Digital Anvil also used 22 R10000 machines (MXI Octanes) and 20 AMD K6 machines to do the rendering. All of the data was kept on an Origin 2000 server that had two RAIDs attached, for a total storage capacity of 850GB. The digital effects were viewed on an Accom 2-eXtreme DDR and edited on an Avid Mediacomposer 8000.
Creating digital models and environments is a complex and challenging process in film spe cial effects production. While decisions resulting in change will occur during any production, conceptualizing provides an architectural framework that must be followed throughout the film. These first steps are important to maintain continuity and help the digital artists design and build efficiently and accurately. The Digital Anvil team who created most of the 240 Wing Commanderdigital effects consisted of 20 artists and technical directors.
Building the Universe
The Wing Commander universe features three sectors of space: the Gateway, Enyo, and Sol. The film describes the territorial conflict be tween two opposing factions: the alien Kilrathi and the human Confederation, each with its unique technologies and architecture. The digital effects team members at Digital Anvil had to reinforce these concepts as they worked.
The art department of Pinewood Studios [England] rendered construction drawings and then built 12" to 48" polystyrene models of the different ships and technologies. After Roberts approved them, the Digital Anvil artists used the polystyrene models as a guide to create technologically specific, accurately scaled, digital models and environments. A major challenge for the artists in creating the 11 digital ships lay in creating complex detail that would look realistic in the extreme scale and close camera proximity of the film. As Olivia said, showcasing digital sequences with extreme close-ups "makes for unique and exciting visuals."
Modeling begins with basic platonic shapes. Shapes are then placed in adjacent and interpenetrating positions to create more complex forms. The details inside the Tiger Claw, for example, represent living quarters, circulation corridors, conveyor systems, communication devices, and other functional constructions. By cleverly using platonic shapes, complex things can be created from simple, recognizable architectural forms Instead of a rectangular room, a more visually dynamic space can be created by mixing many rectangles, cylinders, and spheres.
Curves are drawn and then extruded to generate closed surfaces. The modeler in Maya is a non-uniform rational B-spline (NURBS) modeler. Consequently, the forms are not solid, and all faces must be created to close the shape.
To construct the Wing Commander models efficiently, shapes were built with linear or straight lines, rather than with cubic or curved lines, whenever possible. Linear bevels were also built into all shapes. Bevels replaced the slight natural rounding of actual forms (as in the natural environment, nothing is perfectly flat), because a perfect corner or edge is one of the most obvious computer-generated give aways. Bevels also helped to define the shape in the specular highlights they generated. Digital Anvil artists took great care to bevel every surface down to the smallest detail to insure a complex and realistic look. Each detail was as complex as needed based on the proximity of the cameras as dictated by the storyboards.
The Tiger Claw
The live-action shoot used the interior of the bridge and the hangar doors of the Confederation ship the Tiger Claw. Therefore, the digital model's exterior had to match the actual flight deck doors proportionally as the camera and digital objects move from interior to exterior, or from live action to digital. The miniature reproduction of the Tiger Claw diagrammed the main exterior walls (or shells) and the propulsion system. The Digital Anvil modeler could therefore reproduce the major elements quickly and then concentrate on complex and more realistic detail, including communication and weapons systems.
The Tiger Claw interior shell detail represents a system of architectural relationships - detail is organized similarly to traditional photography techniques by establishing foreground, midground, and background elements. Scott Peterson, Digital Anvil's modeling director, said that using asymmetrical architectural elements increases visual tension, and that by placing special, semi-recognizable detail (such as futuristic communication devices or observation towers), the viewer is pulled into the ship's interior. in addition, the special detail directs attention away from areas with less detail," he said.
The most unusual of all the ships is the Confederation's Rapier. Built full-sized for live-action shooting, the final version failed to duplicate the construction drawings faithfully, prompting Digital Anvil to fly a modeler to the set in the small European country of Luxembourg, so he could measure the ship inch by inch. Several rolls of film were shot of the Rapier from all angles; these images were used to create texture maps for the digital model. While this process is simple in the measurement phase, it soon increases in complexity: The artists must analyze and build the complex and detailed shapes, individual panels, irregularities, and dents in the metal surfaces.
Completed models were textured with color, specular, and bump maps that were wrapped across the surface based on UV coordinates, sometimes referred to as projection mapping. Initially, most of the texture mapping was done using projections, because that technique enables artists to map hundreds of surfaces quickly. The artists could build irregularities into the geometry when needed; because they assigned color, specular, and bump maps during the construction phase, they could render the ships and test the effectiveness of the texture maps continually until the best possible look was obtained with the least memory requirements. The artists created color maps by scanning the high-resolution film plates of existing materials such as Rapier metals and other props. The scanned images were then digitally offset and painted so they could be tiled seamlessly across surfaces.
Fenestration (openings in the outer shell, also windows) was created with geometry and then assigned a transparent or translucent material. Reflection, specular, and bump maps were then applied to complete the look of glass. Additionally, fenestration was created with incandescent color maps that were projected onto the surfaces to indicate windows where functional transparency was not needed. Incandescent window maps created by the artists were not simply white, but have varied colors to add visual interest and suggest interior activity. "It was very important to maintain the original photorealism with little digital alteration. We didn't want a 'painterly' look," said Peterson. Smudge marks and dirt, however, were added to represent wear and tear, while specular and bump maps were used to disrupt the flow of light across the surface and suggested material imperfection.
Once the construction and texturing of the models was complete but before the scene lighting was implemented, the artists lit the ships with self-illuminating lights. These lights were linked or grouped to specific areas of the ship and served multiple purposes, but the main purpose was to indicate functionality, such as interior lighting, headlights, landing lights, and so on. The attenuation of these lights contrasted the harsh directional light commonly found in space, providing for a sense of atmosphere. Furthermore, these lights distinguished functional elements through brightness and color, which helped the audience to identify individual ships and internal spaces. The continuity of ship identification was maintained as ships moved through changing environments.
Once the animatics were approved, general lighting was started for each shot. Artists used animated, flat-shaded models to get a preliminary understanding of the light posilions, colors, and intensities needed Once this was completed, the final backgrounds and models were incorporated and the light placement and coloring refined until the moment the shot was sent to film. The process was additive, beginning with the rough light setup from its sector of space, then customizing each shot with distinct lighting to add character, mood, personality, and a clean composition. Maya scene files were created for each of the sectors and subsectors; these "kits" constitute the basic geometry, textures, and lights for the particular environment. In addition, a slight change in the light setup would occur, depending on environmental elements present, such as reflective light generated from an asteroid belt.
The coloring of lights also helped establish the two separate warring factions and their technological differences. To add to the shot's overall richness, shadows and rim or back lighting were used extensively. These additions give the images more visual impact and were used to separate, or "pop," the objects from the background.
"Whether a ship is firing its guns or engulfed in a huge explosion, interactive lighting is key to completing the illusion of realism," said Oliva, adding that these special lights were incorporated early in the animatic stage. "As an example, [in] the Tiger Claw jump sequence, the interactive lights on the ship's hull from the electrical clouds are not only part of the effect, but visually connect the ship within its environment," he said.
Moreover, lighting CG for live-action plates does not involve the same steps as standalone CG. In this case, careful records and measurements were kept during the live-action shoot, and this information was used to recreate the environment digitally. Lighting placement and color must match exactly to have a believable integration of the CG imagery.
"We wanted the different sectors of space we created, along with the singularities within them, to-be unique and easily distinguishable from one another," said Peterson. "We also wanted to create a visually interesting and dynamic look that would distinguish Wing Commander from the traditional 'star and void' approach of other films."
Avoiding the all-too-common Hubbell Telescope pictures seen in many space films, the digital effects team instead created original production artwork using as reference NASA photography and artwork found in astronomy texts and science fiction books. Working with Photoshop, Maya, and Composer software techniques, these images either inspired the final 3D environments or were incorporated directly as textures. "Creating 3D effects from paintings proved most challenging, especially for the jump-point singularities found in each of the sectors," says Olivia. "These pulsars and quasars became living, breathing entities against the otherwise static backdrops."
Deforming geometry, particles, and animated textures were some of the techniques used to bring these jumps points to life. One way to accomplish this is to introduce natural organic elements into the effect: The animated textures are not merely still images, but moving footage such as animated water, fire, or smoke from reference or source reels. Olivia said that they used atmosphere like qualities in some of the sectors, adding depth and scale to the scenes something not normally experienced in the vacuum of space. Backgrounds of outer space also require the careful placement and composition of these elements combined with the foreground and midground ship for each shot. Artists took care not to overpower the ships with saturated or busy backgrounds; each of the shots exhibits a clear and distinct focus.
Despite the technical requirements for precision, accuracy, and continuity, artistic license occasionally won out. "We tried to make each shot a 'work of art,' which sometimes meant cheating the position or the rotation of a planet or moon," Olivia said.
Wing Commander's animation is stylized and influenced by World War II reference footage, with a slight "hand-held camera" documentary feel. Placing the audience within the action in a "more up-close and personal way gives the shots a kinetic, almost frantic feel," said Olivia. First person point-of-view shots give viewers the same experience of being in a space dogfight with its chaos and confusion that pilots see from the cockpit. Filmmakers used camera shake to center the audience in the battle and let them "feel" the concussions (beginning with a Pearl Harbor-influenced Kilrathi aerial attack on a Confederation base).
Peterson said that keeping CG effects within the bounds of the laws of physics and reality is important so that the illusion of "natural motion" is not destroyed. Olivia agreed, adding that the tendency to overanimate is "one of the problems with CG in film today." He adds that Digital Anvil constantly needed to reduce the speed of objects until they "looked" right. "Initially, we relied on the built - in physics and dynamics of the software for effects such as ships exploding," he said. "However, to increase the dynamic impact, the artists did key framing, which further enhanced the shots. As a result, the sequences in Wing Commander take on a new level of realism and believability."
Winging its Way to a Theater Near You
Wing Commander, directed by Chris Roberts and starring Freddie Prinze, Jr., David Wamer, Matthew Lillard, and Saffron Burrows will be released by 20th Century Fox Pictures in first quarter 1999. More info can be found on the official web site at www.wcmovie.com.
Marshal M. Rosenthal is a writer specializing in digital imaging and computer graphic technologies. A former New Yorker, he now lives in Los Angeles and can be reached at firstname.lastname@example.org.