Command entry: Create panel (Lights) Photometric Click Target Light or Free Light. General Parameters rollout Light Distribution (Type) group Choose Uniform Diffuse from the drop-down list.

Uniform diffuse distribution casts diffuse light in one hemisphere only, as if the light were emitted from a surface.

Uniform diffuse distribution obeys Lambert’s cosine law: the light has the same apparent intensity when viewed from any angle.

Uniform diffuse light distribution