2009

Top: Top view of a target directional light

Bottom: Perspective 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.

A target directional light uses a target object to aim the light.

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

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

NOTE When you add a target directional light, the software automatically assigns

Look At controller on page 3199 to it, with the light's target object assigned as the

Look At target. You can use the controller settings on the Motion panel to assign

any other object in the scene as the Look At target.

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).