Time for action – positional lights in action

1. Open the file ch3_Positional Lighting.html in your HTML5 Internet browser. The page will look similar to the following screenshot:

   

2. The interface of this exercise is very simple. You will notice that there are no sliders to select the ambient and specular properties for the objects or the light source. This has been done deliberately with the objective of focusing on the new element of study—the light position. Unlike in previous exercises, the X, Y, and Z sliders do not represent light direction here. Instead, they allow us to set the light source position. Go ahead and play with them.

3. For clarity, a little sphere representing the position of the light source has been added to the scene. However, this is not generally required.

4. What happens when the light source is located on the surface of the cone or on the surface of the sphere?

5. What happens when the light source is inside the sphere?

6. Now, click on the button Animate. As you would expect, the lighting...