Suggestions for Using the PlaneView3D Applet

To improve the effectiveness of the PlaneView3D tool, the parameter settings for the VRP, VPN, and VUP parameters are reset to appropriate values when a new projection type is selected. By resetting these parameters, a user does not initially have to know the parameter requirements for each subclass. If a parameter is then changed to invalid settings and the Display Projection button is pressed, the view reference coordinate canvas is cleared and an error message is printed inside the Message Box. By viewing the displayed message, a user can set the parameters appropriately.

In addition to the VRP, VPN, and VUP parameters, the selection of a new 3D object has been selected draws the object in the world coordinate canvas, clears the view reference coordinate canvas, and resets parameters for translating, scaling, and rotating the object. See the The PlaneView3D Applet Interface section for a description of the applet's interface.

Recommended Steps in Using the Applet

1. Select various projections from the Projection Type choice box and display the default projection by pressing the Display Projection button.
2. Modify the VRP, VPN, and VUP parameters, then press the Display Projection button.
3. If the view reference coordinate system canvas is cleared then an ERROR has occured. View the Message Box for the error message.
4. Reset the parameters and press the Display Projection button.
5. View the Planar Geometric Projections Tutorial.