Feature: 'Introduction to COLLADA'

For today's exclusive Gamasutra feature, PlayStation 3 graphics architect Rémi Arnaud and Mark Barnes present an extract from COLLADA: Sailing the Gulf of 3D Digital Content Creation, introducing the open standard technique for exchanging normally incompatible 3D assets. In this excerpt, Arnaud and Barnes describe the limitations of the approaches currently taken to exchange data, and how they, in fact, don't improve the situation: "To export the data, developers have to design a format in which to export it. This is no simple task, especially because the format must be flexible enough to withstand changes in requirements during the development process, such as introducing new data types. Once the data is exported, developers still have to write an importer for this data into their content processing facility. Some developers try to solve the problem by having the entire content pipeline contained in the exporter code, so that the output of the export process is directly in the format needed by the runtime. This approach is often problematic since the plug-in interface is not designed to handle such complex applications. It is also the cause of major maintenance problems when the DCC application SDK is evolving and because of the complete lock-in to a given DCC tool and often to a specific version of this tool. Another approach developers take is to limit the input data to the simplest data, such as geometry, texture mapping, images, and animation curves, and to create a set of integrated tools to create the remaining data, often including the game engine as the means to visualize the data. This proves to be a quite successful approach for developers whose goal is to concentrate on a specific subset of game applications and who can create their content with a relatively small team. Such a tool, if well designed and implemented, provides artists and game designers with a very short feedback loop between content creation and its visualization in the runtime. On the other hand, this approach has several limitations. For example, the edits made in the tool cannot be pushed up the pipeline; therefore, if the input data needs to be modified, all the edits have to be done again. Another drawback is that it is impossible to use external technologies without integrating those directly into the tool itself. These approaches are in fact contrary to the improvement of the situation, which should be to require an opening up of the tool pipeline to enable developers to use a variety of independent tools, easing the introduction of new technologies, and making possible the adaptation of the content pipeline to be used by larger teams and for all genres of games." You can now read the full Gamasutra feature with more from on COLLADA as a collaborative approach to organizing and solving the current "zoo" of exchange formats (no registration required, please feel free to link to this column from external websites).