Photo by Randy Tunnell. What''s In A Smile? CG modeler John Feather wields his computer like a sculpting tool.

Under the dim light of a sickle moon, the withered creature Gollum creeps down the rock face like a four-legged spider. His wretched eyes fix on Frodo Baggins and Samwise Gamgee fast asleep in their camp. Gollum has tracked them for weeks. And now he makes his move.

"They''re thieves. They''re filthy little thieves!" he hisses to himself. "Wheeere isssit? They stole it from us. My preciousssss. Curse them! We hates them. It''s ours, it is, and we wants it!"

But Gollum''s blinding desire overshadows his vengeful cunning, and he falls prey to Frodo and Sam''s trap.

These are but a few of the creatures that inhabit Middle-Earth, a fantasy world created five decades ago by J.R.R. Tolkien in his Lord of the Rings masterpiece. State-of-the-art computer graphics (CG) have now brought those creatures to digital life, and Monterey resident John Feather was part of the creative team that made it happen.

Feather, a CG modeler, is at the forefront of technology that continually redraws the lines of what is and what isn''t reality--at least as far as film is concerned. As senior creature technical director for The Two Towers, last year''s second installment in the Lord of the Rings trilogy, he worked with the three-person team that created Gollum''s new, improved face.

Gollum, a hobbit transformed by the evil power of the One Ring, made only a few brief appearances in The Fellowship of the Ring, the first part of the trilogy.

"There was one facial shot of Gollum in the first movie. And if you look closely at it you''ll see that it''s a completely different model than the final model we used in The Two Towers," Feather points out. "He was rebuilt to bear a much closer resemblance to Andy Serkis, who actually acted the part of Gollum."

Feather was born in San Francisco but has lived in Monterey since the age of eight. He started out in graphic arts but always wanted to make films.

In 1998, he started his own video production company, Serpent''s Heart Productions. The following year, a customer asked whether he could include animation in one of his commercials. "It was Frank Green of Green''s Camera," Feather recalls. "He wanted a little anthropomorphic film canister to come out at the end of [the] commercial and say ''See you at Green''s.'' "

Feather said he''d do it, but he didn''t know how. The weekend after receiving the contract, he went to a 3D symposium where he met CG guru Bay Raitt and learned the techniques needed to do the job. A short time later, he found himself developing critters for an animation software company''s Website. When one of that company''s employees left to form 3dMe, he asked Feather to come along. Soon after, Feather became the new company''s technical director.

By this point Raitt had began work on The Lord of the Rings films, and invited Feather to join the project.

Feather generated hundreds of digital sculptures of Gollum''s different facial actions. These digital sculptures, when put together later by the animators, enable Gollum to talk and scowl and whimper and everything in between.

"There are 16 muscles in your face that contribute directly to emotionally connotative expressions," Feather explains. "There are many other muscles, but the ones that really matter for delivering a CG performance are those 16 muscles."

Feather''s primary responsibility was sculpting the discrete action of those muscles, as well as their combined movements. "You have discrete control over most muscles in your face. You can squint one eye. You can tweak one corner of your lip," Feather says while he demonstrates. "But an expression is a symphony of discrete muscular events. Somebody squinting one eye doesn''t really tell you what is going on inside of them.

"Gollum has to go from being this creepy malevolent character to being this pathetic endearing character. And he has to switch back and forth between these two personas throughout the movie."

To create the digital sculptures required to elicit such convincing and compelling performances, Feather used a technique known as subdivision surface modeling. Here, digital sculptures are formed in much the same way as an artist would fashion a statue from a hunk of clay.

Using his modeling software, he starts with a simple three-dimensional block, and then electronically whittles it down to include the details necessary for the particular muscular action being developed. At this point the surface is made up of facets like the cuts on a gemstone. The final step, called rendering, smoothes out all the roughness. And voilá--happy Gollum, sad Gollum.

Feather''s inventiveness did not go unnoticed: The creature''s groundbreaking performance in The Twin Towers brought a fantastic new dimension to synthespians (synthetic thespians) and vactors (virtual actors), so much so that Hollywood was abuzz with the possibility of Gollum receiving an Oscar nomination for best supporting actor.

Hollywood animation has come a long way from Steamboat Willie. "I just fell in love with the process," Feather says.