... This plug-in enables you to add various types of lighting effects to your (RGB) image. ... Directional light . ... Well, you get the idea :) The default settings for this light-type is [-0.5,-0.5,-1.0]. ... Higher values makes your image reflect a lot of light (appear lighter or more intense), while smaller values makes it appear more dull or matte. ... A value of 1.0 makes your image very shiny (bright high-lights) while smaller values makes you image less shiny, making the high-lights dimmer. ...