By Robin Rowe
Shrek was the first major motion picture created primarily using Linux. It won't be the last. Linux is rapidly becoming the professional animator's operating system (OS) of choice, not just at DreamWorks SKG, which produced Shrek, but at top production studios in Hollywood, the Bay Area, and London. An OS that started 10 years ago as a Finnish college student's personal hobby-not even a university research project-is invading film industry servers, renderfarms, and workstations.
Film animators are now using Linux versions of Alias|Wavefront's Maya, No thing Real's Shake, Side Effects' Houdini, and Pixar's RenderMan-the leading commercial applications for animation, compositing, special effects, and rendering. Internally, the studios have ported millions of lines of proprietary code to Linux and are writing more. How did Linux go from a hobby to a professional graphics environment?
It was August 1991 when Linus Torvalds posted this innocent USENIX message about what would later be named Linux: "I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386 (486) AT clones."
 |
I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386 (486) AT clones.
-Linus Torvalds, 1991 |
At that time, the IBM PC was 10 years old, Windows 3.0 was just emerging, and most PC users were still running MS-DOS. The Macintosh OS, which just about everyone agreed was superior to Windows at the time, would soon lose market share to Windows, a cheaper rival that came late to the party but ran on more systems and had broader support. But whether they were Macs or Windows-based systems, PCs were inconsequential to the film industry 10 years ago. Serious graphics work was done on Unix workstations, especially those from SGI.
Indeed, SGI servers and workstations dominated the movie industry because they were good at two things: crunching numbers (for rendering animation), and displaying high-resolution graphics images quickly on the screen. Hollywood may have represented only about 10 percent of SGI's sales, but the company listened to the visual effects community and met its needs, largely because the demands on computers in movie production made it an ideal proving ground for advanced features and applications.
No one, including SGI, anticipated that Intel's relatively puny PC chips would eventually out-perform its workstation rivals-and at a mass-production price that SGI could not match. Meanwhile, the demand for graphics from the PC game mass market were spurring the capabilities of PC graphics cards from companies such as Nvidia to surpass the capabilities of workstations.
 |
| Silicon Grail's Rayz compositor, shown here demonstrating a bluescreen matte, is the first major application designed from inception for Linux, rather than ported from another operating system. |
SGI, reeling under the one-two punch of cheap Intel chips and cheap PC graphics cards, changed direction in 1998 to support PCs. And because Irix, SGI's version of the Unix OS, wouldn't run on PCs, SGI began offering Windows NT-based workstations in 1999. Within months, SGI would change direction again-this time to embrace Linux, a Unix-based OS that runs on PCs.
Although SGI had made the move to Windows, Hollywood had problems making a similar switch for movie production tasks. Over the years, the film industry had created tens of millions of lines of code for its own proprietary tools. But that code was compatible with Irix, not Windows. Code for graphical user interfaces and multitasking code is designed differently in Windows than it is in Irix. And porting all those lines of code to Windows NT was going to require too much work, too many changes.
Another Windows pitfall was support. While SGI listened closely to the film industry, market-driven Microsoft did not. The studios realized they must learn to help themselves. To involve themselves in OS development, necessary for their specialized high performance graphics needs, requires access to the source code and more important, a community of others working to do the same. And, it would be a lot easier to port to a more similar, Unix-based OS. Open source Linux was the obvious choice.
 |
| A variety of software runs on Linux, including Maya, a leading program for film animators (above); Calypso, a plug-in for Maya (above right); and ToonShooter, a proprietary tool from DreamWorks (lower right). |
Titanic, released in 1997, was the first major motion picture to render most of its effects under Linux-using a rack of high-performance DEC Alpha-based servers. Before taking the Linux plunge with Titanic, effects studio Digital Domain had proven that Linux could co-exist with its existing SGI renderfarm working on Dante's Peak. Today, Linux renderfarm technology has matured, to the point where a studio such as Sony can install 100 Linux Intel render servers and have them all running in one hour. Linux machines come preloaded from a manufacturer (such as HP) with software to the studio's specification.
In the past two years, Linux has also emerged as a business for mainstream PC vendors such as IBM, HP, Dell, and Compaq. That market is driven by Linux's popularity as an OS for file servers, particularly for powering Apache Web servers on the Internet. Dell reports that 13 percent of the Intel servers it now sells are Linux-based.
 |
| Popular commercial tools running on Linux provide an end-to-end tool chain. For Captain Corelli's Mandolin from Universal Pictures, this Stuka plane was created with Maya, rendered with motion blur using RenderMan, and composited with live footage usi |
In 2000, IBM committed $1.3 billion to a huge expansion of its Linux efforts. HP has specifically targeted Linux support for the film industry and has helped DreamWorks deploy the OS at its studios. Today, Linux servers, desktop systems, and laptops are available from all four companies.
Making Linux a success on servers and renderfarms was simple compared to the next step: the desktop. The chief obstacle there was video performance. High-performance graphics-card drivers available for Windows were missing in Linux. The task fell to multimedia lead Daryll Strauss working at Precision Insight, now a division of VA Linux. (Strauss was previously with Digital Domain implementing the Titanic renderfarm.) "In 18 months, we built 10 drivers: 3dfx Voodoo 3/4/5, ATI Rage 128/128 Pro/Radeon, Matrox G400, and Intel i810/i815," says Strauss. "Creating a common code base for multiple drivers really saves time."
Besides these accelerated open source drivers, many vendors offer proprietary accelerated Linux drivers, and Linux workstation buyers have many boards to choose from. Nvidia offers Linux drivers for all its cards, including the Quadro2 Pro (about $650 or bundled with Compaq desktops) and GeForce3 (about $400). The Visualize fx5 and fx10 Linux graphics drivers were unveiled by HP last year. HP provides not only drivers, but its own X server. The ATI Fire GL4 graphics board is available with IBM workstations. IBM builds the FireGL chips, but the FireGL board manufacturing was acquired by ATI from Diamond Multimedia. DM had a team in Germany write its Linux driver. No accelerated drivers are available for the newest 3Dlabs boards (Wildcat and Oxygen), but Linux support is promised in the future.
Studios are at various stages of adopting Linux. DreamWorks SKG is the furthest along in deploying Linux systems for animation production. It has more than 200 Linux desktop systems in use by animators and 400 Linux servers. PDI/DreamWorks in Palo Alto uses mostly its own proprietary applications, and in producing Shrek on Linux systems, didn't have to wait for the popular commercial tools becoming available now. DreamWorks studio in Glendale, which produced The Road to El Dorado and Prince of Egypt, is using Linux for its current production of Spirit, Stallion of the Cimarron, due for release in the summer of 2002. DreamWorks has followed three paths to Linux: porting, new development, and encouraging third-party vendors to port popular commercial applications such as Maya and Shake. DreamWorks maintains about three million lines of code itself-almost all of it now ported to Linux-and is expanding production by building a new all-Linux pipeline (studio) at DreamWorks in Glendale, California.
A studio just beginning the Linux transition is Pixar Animation Studios. Vice president of research and development Darwyn Peachey says, "This is the platform that will replace SGI in the CG industry. There's been a lot of progress made since last year. Nobody is wondering 'if' anymore." SGI as a hardware platform is being displaced by high-performance PCs, but the company isn't going away. SGI is actively supporting Linux, both on its hardware and through the Linux port of Maya by subsidiary Alias|Wavefront. Because Linux runs on PC, SGI, and Sun machines, it enables studios to support just one OS.
Like DreamWorks, Pixar faced a massive job in porting its existing code. Pixar finished the Linux port of all its internal software, about two million lines, in May. RenderMan command line tools have been available on Linux since 1999. RenderMan Artist Tools, for use with Linux Maya, are now in beta testing. "Porting went very fast, averaging 2000 lines of code per developer day," says Peachey. "The port to Linux is straightforward, where Windows is difficult." Pixar has more than 500 SGI desktops and uses Sun servers for its renderfarm. About 30 Linux machines are in use for software development, and 20 Linux machines are used in production. By fall, at least 100 Linux desktops are expected to be used in production. Pixar's next film, Finding Nemo (release date summer 2003), is to be produced primarily using Linux systems.
 |
| The Shake compositing application from Nothing Real is just one application popular with the film industry that now runs on the Linux operating system. |
Industrial Light & Magic (ILM) is still porting its code and will begin using Linux on its next movie after Star Wars, Episode II (release date May 2002). Director of research and development Andy Hendrickson says, "We're on schedule to replace about 20 percent of our 600 desktops and 20 percent of our renderfarm with Linux PCs in October. We'll be supporting both Irix and Linux to keep from shocking the system. Right now we're doing a lot of spring cleaning, looking at five million lines of existing code to decide what should be ported and what to retire." ILM uses both its own tools and commercial programs such as Maya and SoftImage.
For flipbook playback of high-resolution movies, ILM has ported its Irix Quicktime-compatible player to Linux. Generally speaking, the players that are available for for Real, Quicktime, MPEG-1, and AVI don't do well above 320-by-240 pixels. But with Linux, says Hendrickson, "we've got flipbook playback of movies working at 1280-by-700 pixels and 24 frames per second-as wide as the typical monitor. We're hoping to bring that to full 2K-by-1K soon." ILM plans to release its flipbook movie player, internal file formats, and batch job scheduler as open source.
It isn't just American studios making the transition to Linux. Double Negative, a division of Universal based in London, has film credits that include Bridget Jones's Diary, The Nutty Professor II, Pitch Black, and Mission Impossible II. Last year Double Negative was called on to create a squadron of Nazi Stuka dive bombers for two motion pictures in simultaneous production: Captain Corelli's Mandolin and Enemy at the Gates. Head of engineering Ian Chisholm points out, "There are no flying Stukas. The planes were made 50 years ago, and you can't get parts." The Stukas were computer generated by animators using Maya for Linux. For compositing, adding effects such as practical explosions and plates, they used Shake running on Linux.
Double Negative avoided Windows by staying with Irix until Linux became practical. Chisholm says skipping NT simplified the Linux transition. "We have a big particle renderer as part of our in-house development that we're using on a submarine movie," says Chisholm, "plus a lot of in-house utilities on Linux." Compositor Adrian Banton says, "Linux is like being on an Irix box. I can use the same hardware at home and have absolute transparency." Double Negative has thus far deployed some 14 Linux dual-processor PCs .
Smaller post-production companies are also moving to Linux. Located in Studio City, California, Hammerhead Productions' credits include Showgirls, Dr. Doolittle II, The Fast and the Furious, X-Men, and Deep Blue Sea. The four founders of the studio had worked at PDI's Los Angeles office until it closed six years ago. Hammerhead has ported its tools to Linux and uses Linux RenderMan. Partner Thad Beier says, "We use GIMP, which is unique among Linux open source tools for being supported by companies in the industry, such as Rhythm & Hues and Silicon Grail." GIMP, an image editor with features similar to Photoshop, provides 16-bit per channel support (64-bit RGBA). It is an example of the leverage obtained by building on someone else's existing open source code.
Silicon Grail in Hollywood is known for its Chalice compositing tool used on movies such as Men in Black, Prince of Egypt, and Deep Blue Sea. Rayz, its latest compositing tool, was designed for Linux from its inception. Silicon Grail acquired the Cineon film-transfer technology from Kodak, and Rayz release 1.2 adds CineSpeed and Cineon grain and de-grain tools. President and founder Ray Feeney is also technical chair of the Santa Monica-based Visual Effects Society (VES). VES has been a focal point for movie technologists, charting a course for the industry's Linux movement and providing a forum for the studios to share lessons learned. Its next major meeting is scheduled for October. (See www.visual-effects-society.org.)
Elsewhere, RPS Data Imaging, a startup in London, is embarking on a high-resolution video-to-film transfer for an entire feature film using its Linux-based software. Technical manager Simon Burley says, "Our software runs exclusively on Linux, and relies on the Direct Rendering Infrastructure in XFree 86 version 4 for real-time previews."
Although commercial animation software is available for Linux, the same is not true for non-linear editing. A significant Linux holdout is Discreet with its fire and combustion tools. Avid Technology, the leading NLE vendor, doesn't offer Linux versions but is reportedly considering it. Its Softimage division, however, has announced Linux support for both Softimage 3D and Softimage XSI.
Nevertheless, Linux is bringing a new level of openness and cooperation to an industry known for its secrecy. Studios are sharing some code back as open source. Being able to support yourself and leverage the work of others is what Linux is all about and it is what is enabling it to take the film industry by storm.
Robin Rowe is a partner of MovieEditor.com, a company that builds video players and editors. He writes a column for Linux Journal magazine (www.linuxjournal.com).
Though Linux has not yet made the same inroads into the CAD/CAM market as it has into film and video production, it does seem to be following the same evolutionary curve for the same reason: Vendors are finding it easier to port their legacy Unix code to Linux than to Windows. In fact, both commercial and open source CAD/ CAM packages are just now emerging, as are modeling kernels, visualization packages, and other tools.
Commercial Linux CAD/CAM packages include the following: VariCAD, a mechanical engineering package that provides 3D modeling, 2D drafting, associate dimensioning, and libraries of machine parts and schematic symbols; Cycas, a 2D/3D architectural drafting and design package offered by Verlag Frese of Ger many; Octree, from German companies FCA GmbH and GbR HNS, a CAD tool for architects working on complex networked projects; and LinuxCAD, from Software Forge, which is intended as a replacement for AutoCAD and Visio.
 |
| Linux Octree CAD, also for architects, provides drawing, modeling, and rendering features. This image was rendered with Linux Radiance, developed with support from the U.S. Department of Energy. |
Linux-based engineering programs include Linux MCS.Patran, which converts CAD geometry into a mesh for computational flu id dynamics or finite element analysis (FEA).
 |
| Commercial Linux-based CAD tools include Cycas, a 2D and 3D architectural design program from Verlag Frese of Germany. |
In terms of open source CAD software, there's Varkon by Microform AB in Sweden, which can be used for drafting, modeling, and visualization or for parametric mod eling and CAD applications development; QCad, a CAD system based on en graving and Laser cutting software called CAM Expert; and FreeDraft, a CAD tool based on the Open Cascade library.
Open source Linux visualization software includes OpenDX, IBM's Open Vis ualization Data Explorer visualization framework, which displays 3D data sets such as anatomy or weather models. Other packages are Ghemical, a molecular-modeling package with 3D-visualization tools; MagCAD, which displays 3D meshes created from medical images such as MRI scans and ultra-sound; and Dia, a Visio-like diagram drawing program based on XML and GTK.
For electronic design automation (EDA), Linux is gaining market fast. EDA market leaders Synopsys, Cadence, and Mentor Graph ics all offer Linux-based tools. More over, he programs are proving their worth. For example, Intel reports that switching to Linux for logic simulation saved the company $24 million while providing twice the performance of the Unix systems that were replaced.
Finally, several leading modeling kernels recently became available for Linux, such as Open Cascade, ACIS, and Para solid, suggesting that more Linux CAD/ CAM applications are on the way.
As in the movie industry, companies find it much easier to port their legacy Unix code to Linux than to Windows. And, the Linux graphics capabilities engineered for the film industry also make the operating system attractive for CAD/CAM.-RR