The Digital Matte Painting Handbook

Cast Shadows

The castle now has light and dark sides, but it still doesn’t look realistic. What is missing are the cast shadows. Cast shadows occur when one surface blocks light that would otherwise illuminate another surface. Cast shadows are generally darker than other shadows on an object, because they receive less fill light. Fill light comes from the sky, the atmosphere, and other objects in the environment that reflect light onto the dark side. Without fill light, objects would be black on the dark side—a lighting situation almost never seen except in outer space. Fill light should never be brighter than the main source of illumination.

Create a new layer at the top of the Form group, name it CastShadows, and set the blending mode to Multiply. ...