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VRML Test Case Generation and Evaluation Using Java



Leonard E. Gebase, Mary C. Brady, Alden A. Dima, Lynne S. Rosenthal


A well-established approach to conformance testing is to treat the implementation being tested as a black box. With this approach, a reference implementation is built to control and evaluate the implementation being tested, and a supporting implementation is built to capture output. For reasons described below, VRML presents special problems that make black box testing impractical. This makes test case evaluation very difficult with VRML, and it reduces the value of automatic test case generation without accompanying improved methods of test case evaluation. At NIST, as part of our Conformance Testing Program, we have developed a Java parser for analyzing VRML files. A parse tree, capturing the entire file contents, is built and syntax checking is done during the parsing phase. The parse tree is then available for performing further analysis on the file's content. In particular, we perform Scene Graph construction and semantic analysis after building the parse tree. Building on this work, we are pursuing the development of a dynamic testing tool and the formulation of a comprehensive testing strategy. We describe an approach to automatic test case generation that takes the work done by the parser in building the parse tree and inverts it. For test case evaluation, our approach emphasizes the browser's reliability in accurately rendering VRML worlds during static testing and emphasizes correct state behavior during dynamic testing. During dynamic testing, we treat the implementation being tested as a finite state machine and use the state transition to identify points where the implementation is to be evaluated. Taking our lead from black box testing, we empoly a methodology in which we simulate VRML browser behavior to aid in dynamic test case evaluation. We conjecture that if the reliability of the browser in rendering VRML worlds can be established during the first phase of testing, then the dynamic testing phase can be automated.
Proceedings Title
Virtual Environments Conference and 4th Eurographics Workshop
Conference Dates
June 16-18, 1998
Conference Location
Stuttgarg, GE
Conference Title
Virtual Environments Conference


black box testing, conformance testing, finite state machine, Java, parse tree, Scene Graph, simulation, test case generation, VRML


Gebase, L. , Brady, M. , Dima, A. and Rosenthal, L. (1998), VRML Test Case Generation and Evaluation Using Java, Virtual Environments Conference and 4th Eurographics Workshop, Stuttgarg, GE (Accessed June 15, 2024)


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Created June 1, 1998, Updated February 17, 2017