The Light Select Render Element represents the lighting contribution from one or more user-selected lights in the scene. Each Light Select channel can output the selected lights' raw, diffuse, or specular contributions to the illumination, or the overall (normal) light contribution. When multiple lights are selected for one Light Select Render Element, all contributions from those lights are combined into that one render element. Multiple Light Select passes can be rendered for a single scene, and lights may be included in more than one Light Select pass.
This element is similar to the Lighting Render Element. However, the Lighting element combines the effect of all lights in the scene while the Light Select element allows for just a user-selected light or set of lights to be broken out; showing their own individual effect(s) on the scene's illumination. By using these render elements, specific lights in the resulting render can be adjusted (color, temperature, brightness, etc.) in a composite without the need for re-rendering.
For example, by generating a Light Select element for all of the backlights in a scene, an artist may adjust the backlighting of the rendered scene easily in the composite, without affecting the rest of the scene's illumination.
