environment

This geometry node defines a sphere of infinite radius. Its only purpose is to render environment lights, solar lights and directional lights; lights which cannot be efficiently modeled using area lights. In practical terms, this node is no different than a geometry node with the exception of shader execution semantics: there is no surface position P, only a direction I (refer to lighting guidelines for more practical details). The following node attribute is recognized:

Specifies the cone angle representing the region of the sphere to be sampled. The angle is measured around the Z+ axis. If the angle is set to 0, the environment describes a directional light. Refer to lighting guidelines for more about how to specify light sources.