Lighting Applet

This applet allows you to experiment with various parameters of a lighting model. The relevant reading is paragraph 14.2 of Hearn & Baker, especially pages 497-504. A few notes:

There's one light in the scene, at the position of the white cross-hair. The light is white, and its intensity is I_l.
Specular highlights are done using Phong's shading model.
The spheres are raytraced individually, going from the furthest to the closest sphere. This means you won't see any shadows.
If you run this applet on anything less than a 24-bit colour display, the resulting pictures are not going to be that pretty.
When running this applet under older versions (< 4.x) of Netscape, the function "copy image to window" doesn't work properly: whenever it is redrawn, it shows the current picture. When run using the Appletviewer, it should work fine though.

Click here for a list of all applets.

For those of you without the book, an explanation of the lighting model parameters:

k_a	material's ambient coefficient
I_a	ambient light (R, G and B)
k_d	material's diffuse coefficient
I_l	light (at crosshair) intensity (R, G and B)
N	surface normal at point of intersection
L	vector to light from point of intersection
k_s	material's specular coefficient
V	vector to viewer from point of intersection
R	vector L reflected at point of intersection
n_s	material's specular reflection parameter

Patrick Min, CS Department, Princeton University

Last modified: Mon Jan 18 15:18:29 EST 1999