Unity Game Optimization - Third Edition

Using culling masks

A Light component's Culling Mask property is a layer-based mask that can be used to limit the objects that will be affected by the given light. This is an effective way of reducing lighting overhead, assuming that the layer interactions also make sense with how we are using layers for physics optimization. Objects can only be a part of a single layer, and reducing physics overhead probably trumps lighting overhead in most cases; hence, if there is a conflict, then this may not be the ideal approach.

Note that there is limited support for Culling Masks when using Deferred Shading. Due to the way it treats lighting in a very global fashion, only four Layers can be disabled from the mask, limiting our ability to optimize ...