VRML testing: making VRML worlds look the same everywhere

NIST tools address problems posed by testing 3D graphics. The article explains the test development strategy and design issues in developing and delivering these testing tools. In 1996, NIST staff met with interested members of the VRML community to discuss various approaches to testing the Virtual Reality Modeling Language (VRML) specification. The standard defines requirements for creating VRML worlds, tools that generate VRML worlds (authoring tools), and tools that interpret and properly render VRML worlds (browsers). It was agreed that VRML worlds, whether generated by hand or through an authoring tool, must be fully compliant with the standard. Furthermore, they must be viewable and reasonably similar in a variety of VRML browsers, regardless of the underlying hardware and software platforms. Consequently, NIST developed metrology tools to support testing VRML content, authoring tools, and browsers. VRML content and the associated authoring tools are tested using a locally developed reference parser, Viper. VRML browsers are tested using a test suite of conformant files, called the VRML Test Suite (VTS). The VTS tests the VRML built-in nodes, VRML extensible components, and base execution model. Finally, the true dynamic nature of VRML is tested using automatic test generation techniques built through extension of the Viper source code. We also address using the Web as a vehicle for delivering these metrology tools.