Siggraph 1998 - Matte Painting in the Digital Age

The Truman Show: Almost 3-D

For the film "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 3-D 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 3-D. First, we need to get 3-D rendering to look completely real.

3-D Lighting Techniques

So, why does 3-D often look like a flat, animated cartoon? Well, it's because most 3-D 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. Again, 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.

Conclusion

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.