Authorability A Flexibility B Consistency C 5.3. Content Management Content managers include those responsible for receiving, validating, archiving, and later retreiving 3D content. The 3D market today is highly author-centric. Grammar features are added to enable authors to create complex and compelling content. Those same features prevent reliable content validation.
Scripts are the prime example.
Inclusion of script support blocks some completeness and syntax checking, forcing content validation to be incomplete and problematic. With the exception of product definition grammars, like STEP, shape grammars are primarily focused upon creating an interesting presentation. Grammar features have a low semantic level that makes content searching impossible. Whether ISO VRML 97, or any other shape grammar is used, all grammars track changes in the 3D market and the technologies in that market. New features are added to grammars, and old ones deleted.