A
light group is similar to a
light clip group in that is intended to constrain the contributions of a set of lights. A light group instead requires the cooperation of a renderer that can mark groups of
instances using the
stencil component of the current
geometry buffer. At most
15 light groups can be present in a given scene, and for a given light group
n, only instances in group
n will be affected by lights in group
n. By default, if a group is not otherwise specified, all lights and instances are rendered in group
1.