Time for Action: Positional Lights in Action

Let's cover an example of positional lights in action:

1. Open the ch03_07_positional_lighting.html file in your browser. The page will look similar to the following screenshot:

2. The interface of this exercise is very simple. You can use the controls widget to interact with the scene. Unlike in previous exercises, the Translate 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 to visualize the light source, but this is not generally required.
4. What happens when the light source is located on the surface of the cone versus on the surface of the sphere?
5. What happens when the light source is inside the sphere?

6. Let's take a look at...