Issue: Volume: 23 Issue: 6 (June 2000)

Growing Pains

Seeing the digital forest through the trees in a Dodge truck television commercial

By Audrey Doyle

It can take Mother Nature 60 years to grow a single redwood tree to a height of 130 feet. In "Off Road," a television commercial advertising the Dodge RAM 4x4 off-road vehicle, Digital Domain grows a square-mile section of redwood forest, including eight types of vegetation, in less than 30 seconds.

Created for agency BBDO (Detroit), the spot begins with the truck in a stark white space. As the camera pans across the truck and the vehicle slowly rotates, out of the void a lush, photorealistic forest begins to grow, complete with redwood and deciduous trees, two types of ferns, sorrel, bushes, clover, and a sparkling stream. Simultaneously, mountains and a skyline unfold in the background so that by the end of the spot, the truck appears to be deep in the middle of a majestic redwood forest. Approximately 97% of the forest is computer-generated; the only live-action elements in the commercial are the truck, the stream, portions of the sky, and a few of the plants in the foreground.
In a challenging TV spot for Dodge, animators at Digital Domain created a realistic CG forest from the ground up. Typically, artists generate fully developed, rather than growing, vegetation because of the difficulty in making the imagery appear realistic

According to Eric Barba and Les Ekker, co-visual effects supervisors for the spot, this was the most difficult job the Venice, California, studio has worked on in years. "Getting plants and trees to look real as they're growing-making sure the timing and shadows are accurate and the wind is acting realistically on the foliage-is difficult," says Barba. "That's why, typically, computer graphics technology is used to generate developed rather than growing vegetation."

Says Ekker, "Some allergy commercials today show CG vegetation growing before your eyes, but that vegetation has an animated look. Plus, the surrounding landscape in those spots is live action, not CG." In the Dodge spot, nearly the entire landscape is computer-generated. "And even though it's growing as you're watching it, it looks organic," he notes.

Before the digital "foresting," the artists researched the types of vegetation typically found in a Northern California redwood forest, then they analyzed how that vegetation grows. To better understand the growing process, the artists viewed "Panspermia," a short animation created a decade ago by computer graphics pioneer Karl Sims, as well as time-lapse photography of plants growing. "We did not want to reinvent nature; we wanted to reproduce it," says Ekker.

In the beginning of the spot, the truck appears in an all-white set, created in NewTek's (San Antonio, TX) LightWave and composited with the truck footage in Discreet's (Montreal) Flame. Shortly thereafter, the floor of the 3D set cracks in numerous places, from which 3D plants and trees begin to emerge. For the sequence, eight artists were assigned their own vegetation to model and animate. To provide direction as to what plant or tree needed to grow when, Barba, Ekker, and the spot's director, Nick Piper, created a timeline in Microsoft's (Redmond, WA) Excel.

"That was really helpful," Barba says. "It told us things like when the first fern should start growing, when it should finish growing, when the first redwood should start growing, and how everything should mix with what was happening with the mountains and sky."

To model and animate the hero redwoods, the animators used Side Effects Software's (Toronto) Houdini. As a result of Digital Domain's work on the film What Dreams May Come, "we knew how Houdini's L-systems could be used to grow trees," Barba explains. To model and animate the trees in the distance as well as the small plants and shrubs, the team chose LightWave and Dynamic Realities' (Waukesha, WI) Tree Druid LightWave plug-in, which pro vided the desired speed and look. For the ferns, the artists used proprietary software "because the third-party software we tried wasn't giving us the level of realism we needed," Barba adds.
To generate the CG redwood grove, the artists started with a stark-white set created in NewTek's LightWave, with composited film footage of the truck. Using a detailed timetable, animators "grew" 3D images of plants, shrubs, trees, and other vegetation in

In total, the spot has 135 layers of vegetation growth, 40 of which are layers of ferns. Each plant is animated to grow ac cording to its own preset timing, to cast shadows, and to be affected by wind. "Controlling how everything grew and then art-directing it so it looked beautiful was difficult," says Barba. "We had to keep the growth subtle and the camera moves smooth."

Equally challenging was creating the bark on the trees. "We tried to grow it the way it would grow in nature-sort of growing out, and staying in place as the tree matures-but it didn't look natural," says Barba. "So we took a few liberties." The team modeled and animated the bark in Houdini and rendered it in Side Effects' Mantra. For added realism, the artists creating their own bark shader so the bark looked like it was growing rather than stretching. The 3D software for this portion of the spot, as well as for all the other digital vegetation, ran on SGI (Mountain View, CA) 320 NT workstations and IBM (Armonk, NY) IntelliStations.

To model and animate the mountains and sky in the background, Digital Domain's Chris Blythe used a proprietary version of Terra Gen, a scenery renderer for landscapes and skies developed by English programmer Matt Fairclough, that ran on an SGI 320. Digital Domain licensed the software from Fairclough and hired him to continue developing it in-house so the artists could control the growth of landscapes and skies over time. "Using the software, we made these mountains actually thrust out of the ground and grow from nothing," says Ekker. "TerraGen handled the forms, textures, and surfaces."

Although all the mountains were created in TerraGen, the sky transitions from a TerraGen sky in the beginning of the spot to a combination TerraGen/live-action sky toward the end. "We shot some motion-control passes-some of them at very low frame rates-on real sky footage because we wanted to get a time-lapse look to the footage so we could see the sky evolving the same way the mountains were evolving," explains Ekker. For initial compositing of all the CG and real elements, Barba used the studio's Nuke software; for final compositing, Digital Domain's Pete Joppling used Flame.

Shooting the truck footage was as arduous as modeling and animating the vegetation. Using Alias|Wavefront's (Toronto) Maya, the team previsualized the camera moves, then moved to a live-action set built on a large turntable outside a hangar at Van Nuys Airport in California. The set was dressed with real ferns, mulch, moss, rocks, and a stream created with actual water and a circulation pump, which were placed around the immediate footprint of the truck.

"We used real water because it would have been difficult to create a CG stream and show it from different angles while tracking it to the landscape the truck was sitting in," explains Ekker. Real plants were also used, he says, because the agency and client wanted the area immediately surrounding the truck to remain photographic. "But very little of the real foliage ended up in the commercial," he adds, "because our 3D foliage looked better."

The live-action team shot motion-control footage of the truck as the turntable rotated 120 degrees and a Fischer box-a lighting system generally used in advertising to give a "liquid-light" look to vehicles-shone from above. The team shot approximately 45 motion-controlled lighting passes on the truck and combined them in Flame. "We lit the truck piece by piece, concentrating on one area and making sure the lighting was perfect, shooting the footage, then repositioning the lights and concentrating on the next area, until we covered the entire truck," Ekker says. "Advertisers like to see light spilling all over the bodywork of their cars."

To add reflections of the digital forest to the body of the truck, the CG team created a LightWave version of the vehicle and animated the forest growing around it. Then they composited more than 60 reflections from the CG truck onto the real truck using Flame. To make sure the CG truck tracked perfectly with the real one, the team used Digital Domain's Track 3D tracking program. Rotoscoping was accomplished in Avid's (Tewksbury, MA) ElasticReality.

Although creating this spot took about 10 weeks of challenging work, the end result was somewhat of a milestone for Digital Do main. "When we started, we knew it would be a difficult project," Ekker says. "We knew technology existed to make things grow, but we had never done this sort of thing ourselves."

Freelance writer Audrey Doyle is a Computer Graphics World contributing editor and former editor-in-chief of Digital Magic. She can be reached at

Houdini, Side Effects Software (

LightWave, NewTek (