This function will modify a picture to draw shadows behind mountains.

After selecting this feature you will be asked to set 2 parameters:

1. Light elevation angle in degrees
2. Light reduction factor in percentage

Light elevation.

This is the angle in degrees where level is reference under which the light is illuminating the picture. Th licht is always positioned at the upper-left cornere.

Light reduction factor.

This is the grade of black on the scale from 0% to 100% where 100% is fully black and 0% is completely transparent.

Example.

The following example is having shades with a light elevation of 10% and reduction factor of 50%.