For films like Stealth, it takes serious rendering power to get the vfx off the ground. © Sony Pictures. Courtesy of Digital Domain.

In the movie Stealth, futuristic warplanes fly at supersonic speed and perform dizzying aerial stunts. “Those are CG planes throughout the whole film,” boasts Darin K. Grant, director of technology for Digital Domain. “Actors were seated in a motion base with a cockpit before a greenscreen,” Grant says. “We provided effects, including tracking each turn of the head to make sure the plane canopy and pilot’s helmet visor did not reflect green.”

From creating complicated 3D machinery to touching up a frame to ensure a component looks consistent and real, computer rendering too seems to be flying ahead at supersonic speed. What might have been a “wow” effect five years ago is now often considered the norm, and companies are constantly raising the bar.

“Today’s complex scene is tomorrow’s `toy’ scene,” offers Larry Gritz, chief architect, Gelato Rendering System, NVIDIA. “The trend is to make things more and more complex.”

Today’s render artists have exciting new tools at their fingertips to make those complex scenes a reality — faster, more powerful computers complemented by top-performing rendering solutions such as RenderMan, mental ray, Brazil and Gelato — and new software such as Maxwell Render.

“There are more rendering options. There are more renderers. High-end rendering solutions are becoming favored as more artists try to achieve complex results,” observes Stephen Regelous, founder and product manager, Massive Software, whose Oscar-winning AI-based crowd simulation system makes visual effects scenes involving hundreds of thousands of digital characters a practical reality. “Also, there are more RenderMan-competitive rendering solutions, such as those from Air and 3Delight.”

”The availability and use of high-end rendering has changed what people are doing with rendering as well,” Regelous continues. “Global illumination has gone from being esoteric to fairly standard. Whereas only two years ago, people were writing papers about how you could do subsurface scattering, now many facilities have developed a subsurface scattering technique.”

“Animation and visual effects are now expected to have very `expensive’ features — ray tracing, global illumination, ambient occlusion, etc. — in practically every shot,” adds Gritz. “By `expensive,’ we are referring more to the time and compute power required, not a pure dollar cost. But as you can imagine, the cost of systems used in a studio environment can be high, and the salaries paid to their employers even higher.”

Ironically in the world of vfx, the best effects are often the ones not immediately noticeable on the big or little screen. “Our goal is to make work look invisible,” suggests Brazil’s Scott Kirvin, ceo of Splutterfish, makers of the Brazil rendering system. “Brazil is good at that… the natural lighting tools are easy to use and the lights behave like lights.”

Despite better software, skilled animators and more powerful computers, render times are not necessarily getting faster. “The bar is rising all the time. Finding Nemo raised the bar and look,” says Chris Ford, business director, RenderMan, Pixar Animation Studios. “Look at the Star Wars movies, which require staggering complexity. Work will expand to capacity. It can still take an hour, or two, to render one frame.”