Once the high and low-res polygonal models had been made, the correct scale and orientation for each dinosaur had to be set, so as to match the camera and scene data for each shot. This was a critical part of how FrameStore saved expense as almost all of the background and many foreground shots were practicals, shot on location in New Zealand and other exotic tropical locales where flora, like ferns, resemble those of the prehistoric periods depicted in the show.

Science meets imagination when creating the skin tones for the beasts. © BBC/Discovery Channel.

Skinning a Dino
Since no one will likely ever know what dinosaur skin looked like, textures and colors for the CG dinosaur skin was derived through a best scientific guess process of understanding the animals' habitats, their lifestyle, whether they were carnivores or herbivores, and body size as larger animals tend to have duller skin colors. But Daren Horley, responsible for designing the dinosaurs' skin, despite being fortunate enough to have a sample of an impression of actual dinosaur skin sent to him, nonetheless found himself having to compromise on a few things. "I discovered that to make the scale texture [of dinosaur skin] show up on television, I had to make [the scales] reasonably large," he says. "It became an informed compromise between what was scientifically accurate and what looked right on-screen."

Once the BBC producers had approved the designs for the skin colors a bump map was made. A bump map is a black and white 2D image that the software will see as bumps or surface irregularities for shadow and highlight detail. A color map was then painted over the bump map and the resultant skin image wrapped around the 3D model, very much like a tight-fitting suit.

Splashes were captured to bring authenticity to the million year old environments. © BBC/Discovery Channel.

How Do You Move a 70 Ton Dino? By Hand, Naturally!
A very interesting fact that has emerged from how the FrameStore's relatively small staff made 40 dinosaurs come to life was that animal movements were largely the result of hand animation, an extremely laborious and time-consuming process. But for this kind of show Mike Milne and his animators saw early on that hand animation (moves made manually on the computer as opposed to allowing the computer to keyframe, or do the calculation automatically), was going to have to be the way to go. "The only way we could achieve convincing animation, the little wobbles here and there and the way the underlying structures of the skin change with movement, was to animate the dinos by hand," says Milne.

Since many of the backgrounds and foregrounds were already filmed (along with the movements of trees, splashing of water and other actual footage), FrameStore's animators had to be doubly attentive to shot details. To again simplify the animation process, the animators used low-res models with stick and ball skeletons in much the way puppeteers manipulate a puppet's body parts to make them move. This created extremely convincing animation, as the animators were able to control the dinosaurs' movements 100% of the time, a single frame at a time, thus maximizing their naturalness when composited with the live-action footage.

The Real Deal
But were the dinos' movements going to be convincing enough? Since no one actually knew how a T-Rex's forelimbs would move, how would the animators make it look natural on-screen? True to the remarkable attention to details given this production, a decision was made early on to use, among other things, live elephants to "model" dinosaur movement for the animators to study and use.

Inferring what they already knew from their own experience as character animators, as well as consulting paleontologists as to the actual dynamics of the gigantic joints, tendons and muscles of dinosaurs, the FrameStore team was now able to use more than just an educated guess to fancy precisely how these gigantic animals would movethey could apply the dynamics to T-Rex's forelimbs in a way never before seen in motion graphic depictions of their movements.