Fog() -
Constructor for class simogl.effect.fog.Fog
Creates a new Fog object with the following default properties:
Fog mode: EXP
Color: RGBA parameters all 1.0f (pure white fog)
Density: 1.0f
Start/End: 0.0f/1.0f
Remember to enable the use of fog with the setEnabled()-method,
because it is disabled by default