2009

Top: Perspective view of a free directional light

Bottom: Top view of the same light

Directional lights cast parallel light rays in a single direction, as the sun does

(for all practical purposes) at the surface of the earth. Directional lights are

primarily used to simulate sunlight. You can adjust the color of the light and

position and rotate the light in 3D space.

Unlike a targeted directional light, a Free Direct light has no target object. You

can move and rotate the light object to aim it in any direction.

A Free Direct light is used when you select a Standard sun in your

Daylight

system

on page 5139.

Because directional rays are parallel, directional lights have a beam in the

shape of a circular or rectangular prism instead of a "cone."

NOTE Direct lights are supported in a radiosity solution on page 6168 only if they

are pointed downwards, outside the boundary box of the scene geometry.

NOTE The mental ray renderer assumes that all directional lights come from

infinity, so objects that are behind the direct light object in the 3ds Max scene

will also be illuminated. In addition, with the mental ray renderer, directional lights

cannot generate area shadows, and do not work with the Beam shader (in the

lume library).