The Spot Light provides light that radiates in a cone pattern.
It appears in the scene as a yellow wireframe cone.
Unlike the Point light, you can aim the Spot Light by rotating
it.
Spot lights are most effective when they are used to light complex
planes (floors, walls).
Here is an experiment that demonstrates the effect of a spot
light.
From the main menu select Scene->Clear.
Set the Camera to the default Perspective settings by
selecting Camera->Perspective from
the main menu.
If the Scene Properties windows in not visible, select Window->Scene
Properties from the main menu.
Press the New Object button on the Scene
Properties window and select floor.
On the Object Properties window select Complex.
Click on the Material tab in the Object
Properties window.
Select the preset material Obsidian.
On the Scene Properties window, click the New
Light button and select Spot.
Click the Move button on the toolbar.
Move the light to the into the scene by moving the mouse
to the up while pressing the left mouse button. Watch the
status bar in the lower left corner of the screen, move
the light in until the Z value reaches about 0.000.
Click on the Rotate button on the
toolbar.
Rotate the light down by moving the mouse to the left
while holding the left mouse button. Watch the status bar
in the lower left corner of the screen, move the light in
until the Y value reaches about -1.000.
Click on the Spot tab in the Object
Properties window.
Move the Cutoff slider right to about
50.
Now smooth out the circle by slowly moving the Exponent
slider to the right.