The scene graph is the data structure defined in VRML. Files using a WRL extension describe the three-dimensional world, including the objects it contains, their properties, and how they interact. As in HTML, developers can link external media--such as graphic textures or sound files. Also like HTML, scene graph files are simple text files. Work is under way to create a binary (nontext) file format for VRML that should dramatically decrease scene-graph file sizes.
See also: VRML