X3D Validator Available for X3D Scenes
X3D authors now have an excellent new tool for checking their scenes. The X3D Validator bundles a comprehensive suite of tests to help with Quality Assurance (QA) of X3D scenes and metadata. Because X3D has an XML encoding, multiple Web-based verification checks have been integrated into a single comprehensive tool. Validation tests include:
- XML header and DOCTYPE checking for correct document headers
- Well-formed XML checking
- X3D DTD and XML Schema checking for valid X3D nodes, fields and values
- X3D Schematron rule checking to verify semantic correctness and detect internal-consistency problems
- X3D to ClassicVRML conversion checks a variety of legal X3D constructs
- Regular expression checking for malformed floating-point numbers and excess leading zeros
- X3D to XHTML pretty-print listing to check online URL links and to document ROUTE connections
Eliminating errors and warnings makes X3D content more portable and reliable. All of the several thousand scenes that are checked into the X3D Example Archives undergo these checks each night through continuous-integration Jenkins builds. This work is entirely open source and produced by the Naval Postgraduate School (NPS) Modeling, Virtual Environments and Simulation (MOVES) Institute. The test suite is quite flexible and is capable of running via a Web server, in authoring tools (such as X3D-Edit), as part of conversion tool chains, and in offline build processes. The X3D Specifications, produced by the Web3D Consortium for the International Standards Organization (ISO), remains the authoritative formal reference for determining correctness of all X3D scenes.
I have used the X3D Validator in the development of the STEP to X3D translation software that is part of the STEP file browsing web application at http://spri.kshell.com. The Validator has already served to identify systematic errors in the automatic generation of X3D models from CAD specifications, and will continue to be part of the Test-Driven Development of this translation software.
The online X3D Validator, and the matching validation capabilities in X3D-Edit, are very reliable and convenient. PartDB makes good use of both tools when improving our X3D translation module for CATIA.
Hyokwang Lee, X3D CAD Working Group cochair
PartDB Co. Ltd., http://partdb.com