Browsing by Author "Hodges, Larry F."

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    Maintaining Spatial Orientation during Travel in an Immersive Virtual Environment
    Bowman, Douglas A.; Davis, Elizabeth T.; Hodges, Larry F.; Badre, Albert N. (MIT Press, 1999-12-01)
    An experiment is presented comparing the effects of various virtual travel techniques in an immersive virtual environment (VE) on the spatial orientation of users. The experiment was designed and implemented in the context of a formal framework for the design and evaluation of VE travel techniques. Subjects traveled through virtual corridors, noting the location of objects along the way, and were asked to point in the direction of one of these objects when the end of the corridor was reached. Results indicate that virtual travel techniques, in which users do not physically translate their bodies, can allow the maintenance of a user's spatial orientation as measured by a pointing task. The experiment also replicates an earlier result, showing that path dimension significantly affects user performance. Finally, the strategies used by subjects to perform the task were shown to be significant, indicating that performance depends not only on the technique, environment, and task, but also on the sophistication of the user.
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    The simple virtual environment library: An extensible framework for building VE applications
    Kessler, G. D.; Bowman, Douglas A.; Hodges, Larry F. (MIT Press, 2000-04-01)
    As virtual environment (VE) technology becomes accessible to (and affordable for) an ever-widening audience of users, the demand for VE applications will increase. Tools that assist and facilitate the development of these applications, therefore, will also be in demand. To support our efforts in quickly designing and implementing VE applications, we have developed the Simple Virtual Environment (SVE) library. In this article, we describe the characteristics of the library that support the development of both simple and complex VE applications. Simple applications are created by novice programmers or for rapid prototyping. More-complex applications incorporate new user input and output devices, as well as new techniques for user interaction, rendering, or animation. The SVE library provides more-comprehensive support for developing new VE applications and better supports the various device configurations of VE applications than current systems for 3-D graphical applications. The development of simple VE applications is supported through provided default interaction, rendering, and user input and output device handling. The library's framework includes an execution framework that provides structure for incrementally adding complexity to selected tasks of an application, and an environment model that provides a layer of abstraction between the application and the device configuration actually used at runtime. This design supports rapid development of VE applications through incremental development, code reuse, and independence from hardware resources during the development.
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    Testbed evaluation of virtual environment interaction techniques
    Bowman, Douglas A.; Johnson, D. B.; Hodges, Larry F. (MIT Press, 2001-02-01)
    As immersive virtual environment (VE) applications become more complex, it is clear that we need a firm understanding of the principles of VE interaction. In particular, designers need guidance in choosing three-dimensional interaction techniques. In this paper, we present a systematic approach, testbed evaluation, for the assessment of interaction techniques for VEs. Testbed evaluation uses formal frameworks and formal experiments with multiple independent and dependent variables to obtain a wide range of performance data for VE interaction techniques. We present two testbed experiments, covering techniques for the common VE tasks of travel and object selection/manipulation. The results of these experiments allow us to form general guidelines for VE interaction and to provide an empirical basis for choosing interaction techniques in VE applications. Evaluation of a real-world VE system based on the testbed results indicates that this approach can produce substantial improvements in usability.
  • Testbed Evaluation of Virtual Environment Interaction Techniques
    Bowman, Douglas A.; Johnson, D.; Hodges, Larry F. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2001)
    Testbed Evaluation of Virtual Environment Interaction Techniques