3D Design - April 99 - From CD to Silverscreen
3D Design - April 99 - From CD to Silverscreen
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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
PICTURE CAPTIONS:
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.
ARTICLE
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.
Design Conception
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."
Digital Modeling
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.
Model Texturing
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.
Self-Illumination
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.
Lighting
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.
Environments
"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.
Animation
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
marshalr@pipeline.com.
