Collada: Game On

Console manufacturers are at the mercy of the game development community. The success of a new console depends a great deal on the number of games available to support it at launch. If the game developers can’t deliver a compelling slate of games to coincide with the delivery of a new console, such as the Sony PlayStation 3, for example, it could easily slow down consumer acceptance of the product.

Sony proposes a solution in Collada, or Collaborative Design Activity, an XML schema that offers an intermediate format for game developers to losslessly exchange asset data between authoring tools. A tool-neutral, open standard that recognizes the complexity of authored 3D data, Collada enables developers to mix and match tools from different vendors to create their own customized tool chains. The Collada XML schema enables a description of a database or directory so that data can be exchanged with all its components-including multiple versions of the same assets intended for different purposes or targets.

Perhaps a little history is in order. Back in 1999, and earlier, as Sony was preparing for the PlayStation 2, Sony’s engineers knew that the platform would be challenging for developers. The company created a middleware program to encourage the development of tools to make content creation easier for those targeting the PlayStation 2. The program was a limited success. There are plenty of middleware tools available, but often game developers have to adapt the tools to their own uses and applications. Sony found that game developers themselves were too embattled to create their own tools. The idea of Collada is an expandable one that intends to build a framework for data creation and exchange that will provide a clear set of procedures as well as standards and formats for developers, allowing them to access, track, and exchange assets. Rather than encouraging companies to build tools, Collada functions as a pool that will grow in usefulness as companies contribute.


In the next step to making Collada more useful, Sony has made the format open to Khronos, an industry consortium founded in 2002 dedicated to creating tools and APIs that enable the authoring and playback of rich media on different platforms and devices.

Announced at SIGGRAPH 2005, Collada is a Khronos working group. As such, it is part of the open standards movement and is offered royalty free. Khronos has proven itself to be a practical resource for companies that need to reach common ground, in spite of the fact that they may be competitors or tangentially related. And, in the case of Collada, competitors Alias, Autodesk Media and Entertainment, and Softimage have signed on to Collada, and so have middleware companies, such as Aegia, Criterion, and Havok, and game developers like Backbone Entertainment and Vicarious Visions. Hardware companies Nvidia, ATI, and 3Dlabs are longtime supporters of Khronos and are likewise supporting Collada.

One of the more interesting developments is that Khronos, Collada, and Alias have agreed to add support for Collada to FBX, which was originally developed by Kaydara to function as a file exchange format. Kaydara was acquired by Alias more than a year ago, and as a result, there has been some concern in the development community about the true “openness” of FBX. As in any situation where a format is exclusively owned by a company, there is a fear that the company will be able to stay ahead of competitors by controlling the format. The fact that FBX is being worked into the Collada framework is a good example of how Collada can be adapted to fit within the production pipelines of game developers. Similarly, the Collada group is seeking to add asset management, and they have developed a specific work group for this purpose. Avid, which offers asset management through its Alienbrain product, is an interested participant in the work group.

Sony, of course, is committed to Collada and plans to support the other Khronos standards as well. It has already announced support for Khronos’s 3D API for embedded systems, OpenGL ES, as its 3D API for PlayStation 3 development. The Collada approach is not limited to Sony PlayStation development; it can be used in any 3D content development pipeline, including Xbox, PC, GameCube, and so on.

While Collada is primarily focused at the 3D modeling and animation portion of the pipeline, the idea is to create architecture capable of supporting an expandable range of capabilities associated with 3D modeling and animation, including physics, for example, and programmable shaders, which can be offered as packages.

At SIGGRAPH this year, the Collada group had presenters from Softimage, Nvidia, Alias, and Aegia, to name a few, demonstrate the exchange of models into and out of Collada. They proved it works. Khronos director Neil Trevett says the real advantage to having Collada in the Khronos family is the ability to keep development and deployment of Collada and OpenGL ES evolving together. “Each is aware of the needs and the opportunities that the other creates,” he says.

Collada is not the first attempt to improve game development, but it represents an ongoing trend in several high-tech industries toward collaboration and open standards. For the game industry, at least, the old way of locking up content in proprietary formats isn’t working. When game developers can’t get their work done, no one wins.