Radial gradients are defined by a

　　element.

　　If the start circle defined by , and lies

　　outside the end circle defined by , , and , effectively

　　a cone is created, touched by the two circles. Areas outside the cone stay untouched by

　　the gradient (transparent black).

　　If the start circle fully overlaps with the end circle, no

　　gradient is drawn. The area stays untouched (transparent black).

　　shows how to fill a rectangle by referencing a radial gradient paint

　　server.