This applet requires a browser which can run applets developed with the JDK 1.1.5 such as Netscape 4.5, appletviewer or HotJava.

Instructions on how to use this applet are below. Also, this applet will take several seconds to initialize itself before the initial image is displayed, so please be patient.

This is an applet which displays a scene rendered using a Phong specular illumination model, texture mapping, and your choice of shading models: None, Flat, Gouraud, or Phong. None is just that: no shading model is used and the scene is displayed using the colors it was defined with. Flat shading is where the lighting equation is evaluated once per rendered polygon. Gouraud shading is where the lighting equation is evaluated once per vertex of each rendered polygon and then the computed intensity is linearly interpolated across the polygon. Gouraud shading is incompatible with texture mapping and therefore the texture maps will be removed from the display. Phong shading is where the normal vectors are interpolated across the face of the polygon and the lighting equation is evaluated once per pixel drawn.

Initially, the scene is displayed flat-shaded. To change the shader used, select the appropriate radio button in the group to the right of the image. To switch to a wireframe display (much faster but not as pretty) select the "Wireframe" toggle. While in wireframe mode polygon and vertex normals can be displayed by selecting the "Show Normals" toggle. Backface culling can be controlled via the option menu. The option menu has three items: Cull, which will cause the back-facing polygons to be removed; Keep, or don't remove any polygons; and Flip, which will remove the front-facing polygons.

The viewing parameters can be modified via the panel below the image. The editable parameters are Eye Location, Look-at Point, and Up Vector. The Eye location is the spot in world coordinates where the camera is located. The Look-at Point is the spot in world coordinates where the eye is pointing. The Up vector defines which way is up. When one of these parameters is edited, the Apply button must be pressed to implement the changes.

The lighting parameters can be modified via the panel below and to the right of the image. The editable parameters are location, specular-reflection exponent, ambient intensity, and point light source intensity. When a value is modified to implement the change press the Apply button.

J. Scott Hofmann
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Last modified: Tue Apr 14 13:02:33 EDT 1998