This option can be specified only once. If this option is not specified the default is white. A spotlight defines a cone of light. Objects within the cone are illuminated, while objects not inside the cone of light are not affected. Intensity is a numeric which ranges from -1 to 1.
Negative values suck light out of the world while positive values illuminate the world.
The greater the magnitude of the intensity, the more affect it has. Xloc, yloc, and zloc are coordinates which specify the the psition of the tip of the cone in the world. Xdir, ydir, and zdir form a vector specifying the direction in which the cone radiates from the point. Dr, the drop off rate is a numeric in the range 0 to 1 which specifies the rate at which the intensity drops as we move from the center of the cone to an edge. A value of 0 for dr means that objects in the middle of the cone and objects at the edge of the cone are illuminated with equal intensities of light.