Shines a distant light on an image to create a three-dimensional effect.
You control the positioning of the light with azimuth and elevation;
azimuth is measured in degrees off the x axis and elevation is measured
in pixels above the Z axis.
This method is available if Imagick has been compiled against ImageMagick version 6.2.9 or newer.
$imagick = new \Imagick(realpath($image_path));
$imagick->shadeImage(true, 45, 20);