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QTVR Atom Containers

This chapter describes in detail the VR world and node information atom containers. These two atom containers can be obtained by calling the QuickTime VR Manager routines QTVRGetVRWorld and QTVRGetNodeInfo. Those routines are described in this chapter.

If you are unfamiliar with QuickTime atoms and atom containers, you should read the QuickTime File Format specification (see bibliography). The specification describes in detail how QuickTime uses QT atom and atom containers, which are tree-structured hierarchies of QT atoms, to provide a basic structure for storing information in QuickTime.

You need to know about the various atoms contained in the VR world and node information atom containers if you want to extract information from a QuickTime VR file that cannot be obtained using VR Manager functions. For instance, there is no QuickTime VR Manager function that returns the name of a given node; however, you can easily get a node’s name by reading the information in the atoms in the atom container returned by the QTVRGetNodeInfo function.

This chapter is divided into the following major sections:

• “Overview of Atom Containers” describes the QuickTime atom container, a tree structured hierarchy of QT atoms used for storing information in QuickTime files.

• “Getting the Name of a Node” discusses how you can use standard QuickTime atom container functions to retrieve the information in a node header atom.

• “Adding Custom Atoms in a QuickTime VR Movie” describes how you can add custom atoms to either the VR world or node information atom containers.

• “Required Atoms for Wired Actions” discusses what atoms must be included in the QuickTime VR file to support wired actions.

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