In this final chapter, we will describe the use of Java 3D as a visualization technology in the development of a Web-based 3D real time oscilloscope experiment. Developed and launched under a research project at the National University of Singapore, this application enables students to carry out a physical electronic experiment that involves the use of an actual oscilloscope, a signal generator and a circuit board remotely through the Internet (Ko 2000, and 2001). Specifically, this system addresses 3D visualization schemes on the client side (Bund, 2005, Hobona, 2006, Liang, 2006, Ueda, 2006, Wang, 2006), as well as Web-based real time control and 3D-based monitoring between the client and server (Nielsen, 2006; Qin, Harrison, West, & Wright, 2004). The control of the various instruments are carried out in real time through the use of a Java 3D based interface on the client side, with the results of the experiment being also reflected or displayed appropriately on 3D instruments in the same interface.
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In this final chapter, we will describe the use of Java 3D as a visualization technology in the development of a Web-based 3D real time oscilloscope experiment.
Developed and launched under a research project at the National University of Singapore, this application enables students to carry out a physical electronic experiment that involves the use of an actual oscilloscope, a signal generator and a circuit board remotely through the Internet (Ko 2000, and 2001). Specifically, this system addresses 3D visualization schemes on the client side (Bund, 2005, Hobona, 2006, Liang, 2006, Ueda, 2006, Wang, 2006), as well as Web-based real time control and 3D-based monitoring between the client and server (Nielsen, 2006; Qin, Harrison, West, & Wright, 2004).
The control of the various instruments are carried out in real time through the use of a Java 3D based interface on the client side, with the results of the experiment being also reflected or displayed appropriately on 3D instruments in the same interface.
Basically, Java 3D is used to create a virtual 3D world or room in which the 3D instruments reside. The mouse is used for both navigation in this world as well as to operate the instruments through, say, dragging a sliding control or a rotary control or clicking or switching appropriate buttons on the instruments. Associated commands that cause the real instruments in a remote physical laboratory to operate accordingly are then sent through the Internet in real-time. Experimental results corresponding to, say, a change in the real oscilloscope display, are then sent from the instrument control server back to the Java 3D client to result in a real-time change in the display of the virtual 3D oscilloscope in the virtual 3D world.
Figures 1 and 2 show some screen capture of the application. Specifically, Figure 1 shows the initial scene of the virtual laboratory room for carrying out the experiment. Note that the experiment and apparatus are inside the room and the user has to make use of the navigational controls at the bottom of the screen to “walk” toward the room and open the door after typing an user access password. The bottom rightmost control allows the user to make turns in four possible directions, while a similarly shaped adjacent control on the left allows the user to move linearly. These controls are custom designed for the application and can be activated by using just the mouse, even though keyboard activation is also possible. While this adds an additional level of complexity to the interface and makes it more difficult to develop the program, it is felt to be essential for the users who are primarily students with no experience in using a 3D-based software.
Figure 1 Virtual room in the real-time oscilloscope experiment
Figure 2. Virtual instruments in the real-time oscilloscope experiment