This property is used for making spotlights. Use the Renderer→Light property to define the brightness (intensity) and offset of the spotlight. The brightness set is for the inner cone of the spotlight. The brightness decreases progressively from the inner cone’s intensity to 0 at the outer cone.
Both X and Y data fields are used to define the size of the cones of light leaving the spotlight; X defines the angle in degrees for the inner cone of the spotlight; Y defines the outer cone angle in degrees; the Z data field is not used. You should make sure that Y is always greater than or equal to X.
Property Name: Spotlight