Definitions

Vertical Angle

The light source vertical angle:

•0° is on the horizon i.e. sunrise or sunset.

•90° is from vertically above i.e. midday.

Horizontal Angle

The light source horizontal angle measured relative to the Cartesian coordinate system:

•0° is from the East.

•180° is from the West.

Diffuse Lighting

Diffuse lighting defines degree to which light is scattered on being reflected from the  surface.

Set large values to accentuate surface detail.

Ambient Lighting

Ambient lighting defines the scene lighting intensity.

It is analogous to night/day or sunny/cloudy.

Hint

To accentuate surface detail:

•Use a small vertical angle to simulate sunrise or sunset.

•Use large diffuse lighting values.

•Use mid-level ambient lighting values.