Film GIMP at Rhythm & Hues

Robin introduces Film GIMP, an open-source Linux tool being used in major motion pictures.

The GIMP probably leads any list of killer applications for Linux. This Photoshop-like graphics package is very popular for retouching still images. However, fewer people are aware of its motion picture cousin called Film GIMP, intended for working on a series of images.

Linux is now being adopted in motion picture production at DreamWorks, Pixar, ILM and many other major studios. Most of this Linux effort involves commercial tools such as the popular 3-D animation package Maya (see the article “Alias|Wavefront Maya 4” in the October 2001 issue of Linux Journal) or obscure internal tools representing an investment of millions of lines of code created by the studios themselves (see “DreamWorks Features Linux and Animation”, August 2001 Linux Journal). Today there is just one significant open-source Linux tool being used in major motion pictures. Let's take a look at Film GIMP and its use at Los Angeles film and television commercial postproduction studio Rhythm & Hues.

R&H programmer Caroline Dahllöf is a lead developer and maintainer of Film GIMP. “We use Film GIMP on all talking animal jobs”, says Dahllöf. “Film GIMP is in use in production by various studios but probably is used most by R&H. Other studios say that they think GIMP is a great idea, but we seem to be the only production house currently developing and supporting it.” Dahllöf would like to see other studios become more involved in development. At R&H, Film GIMP has been used in Harry Potter, Cats & Dogs, Dr. Dolittle 2, Little Nicky, How the Grinch Stole Christmas, The 6th Day, Stuart Little and Planet of the Apes. R&H also creates commercials, such as the familiar Coca-Cola bear commercial. Dahllöf says:

Our big thing is talking animals. We'll create those in 3-D because we like the look much better than 2-D morphing. We'll make a 3-D model and track it to the plate, matching the movement of the live animal with a CG animal head. Then the lighting department projects the frame on to 3-D model. The 2-D department fixes missing background parts as the animal talks.

Stretching has to be fixed with textures. The mouth interior is all CG. Some projects, such as the Coke commercial, are all CG. That's a different technique than making live-action animals talk.

As is typical with production studios, R&H uses not just one tool but a pipeline of tools for 3-D animation and live-action special effects. Before looking at Film GIMP, let's examine some of the proprietary tools in the production pipeline that Film GIMP must seamlessly interact with.

Film GIMP Screenshot—Working on

Film GIMP Screenshot—Visa Commercial

3-D Modeling with And

For 3-D modeling, R&H uses an in-house modeling tool called And and Maya. Modeler/TD Yeen-shi Chen explains:

For a TV commercial I am creating a model of a cat wearing a wet suit. The cat model was retrieved from our model library and modified to match the cat in the commercial. The wet suit and diving gear are added later. The entire model was built in And. I create the model in a neutral pose because that makes it easier for the setup people to put a skeleton in it.

Compositing with ICY

Technical Director Jeff McLean explains how R&H uses IC (Interactive Compositing), their internally developed compositor: “A typical task is removing the arms of a skateboarder from a scene in Scooby Doo to be replaced by Scooby in a barrel.” (Scooby Doo is due for release June, 2002.) When McLean replaces a live actor with an animated figure like Scooby, he must not just cover up the actor but handle situations where the actor's movements extend beyond what the animated figure will cover. “I have to do a background replace and repair the missing pieces of the background when I remove an object from a scene”, says McLean.

ICY Screenshot—Canon Commercial