Hey, Im trying to do a spot light shining down onto a quad, and that has a floor texture. I am doing a basketball floor. I cant seem to get just a single spotlight to shine down on it, like all the lights are off in the room except for one shining down in the center of the court putting a circle of light on the floor. Can somone help me out?

The light is interpolated from the vertices of the polygon. If you have one big floor quad so will the result be poor.