The Truman Show - Almost
For 1998's The Truman Show,
director Peter Weir decided to shoot his film on location
in Florida at the resort town of Seaside. This location
already had many buildings that would establish the
film's look of an ultra-clean and recently fabricated
town. However, Seaside needed to be customized by enlarging
the downtown area with office buildings where the Truman
character could work.
The production decided to actually
construct the first story of these buildings so that
close shots of actors entering and leaving them could
be photographed without special effects. But for the
long shots, additional stories of the various buildings
needed to be added using the computer.
|Photography in the town
of Seaside, Florida.
||Final composite establishing
the downtown area.
Again, you can see our wire frame line-up
grid used for camera tracking on the left-hand side
image. On the right we see the rendered texture maps
that are now added to the scene. So you can see that
this is not true 3D yet! As I mentioned earlier, we
call it "two-and-a-half-D."
We're still relying heavily on the matte
artist to "make it work" with his or her artistic ability
to render and mimic the live-action photography with
digital matte painting enhancements. But, the ultimate
goal is for us to work in true 3D. First, we need to
get 3D rendering to look completely real.
3D Lighting Techniques
So, why does 3D often look like a flat,
animated cartoon? Well, it's because most 3D rendering
packages save rendering time by not simulating all the
ways that light energy would be distributed in the real
world. Since we must combine our CG rendering with real
world photography, the area of computer graphics that
we are most interested in is called "true global illumination."
In order to achieve this degree of realism
we use a variety of digital lighting techniques. We
use methods like ray tracing that mimic the direct illumination
from practical light sources, and also radiosity, which
describes the indirect illumination from surfaces in
our virtual environments.
For instance, as I raise this sheet of
paper, the light reaching it is called direct illumination
and is best realized using ray-tracing techniques. But
if I put my other hand next to this sheet of paper,
you'll notice that it is lit more brightly as I bring
it close to the surface, because it's receiving the
bounce light of indirect illumination. Describing this
effect is especially important in night scenes of buildings
with surfaces that would bounce light around and affect
the scene's lighting.
|Live-action plate photographed
in Las Vegas.
||Completed scene with
radiosity rendering techniques.
Take, for example, this scene from the
1995 film Casino, where we worked with Lightscape
Technologies to adapt radiosity algorithms to create
a night scene establishing the Las Vegas of the 1970s.
Director Martin Scorsese wanted to take advantage of
shooting on location in real Las Vegas casinos. Unfortunately,
many of the classic hotels and marquee signs on the
strip were torn down long ago. So, for the exterior
sequences we were asked to create "Virtual Vegas" --
a series of shots of the strip as it appeared in the
desired period. This was the first time Radiosity algorithms
were used to create imagery for a feature film.
We've seen the techniques originally developed
to allow early filmmakers to realize their visions.
We've seen today's filmmakers achieving similar story-telling
goals, but by using technological breakthroughs to solve
the same old film production problems. Matte World and
other digitally-equipped studios have been able to offer
directors the ability move the camera more freely by
re-inventing 2-D matte painting with the help of processes
made possible by computers. So, while the tools the
matte artist uses may have changed from large sheets
of glass and paint brushes to graphic tablets and "global
illumination rendering," the need for people who can
interpret, visualize and mimic photographed reality
is still in high demand - no matter what tools we are
using. Thank you.