Light & Shadow Linking

Table Of Contents


Intro

Scene with all lights affecting all objects Same scene demonstrating light linking Same scene demonstrating shadow linking


By default every light in a scene illuminates and casts a shadow of every object in a scene. However there are times when you want specific lights to only affect certain objects. Even further than that you might want a certain light to illuminate an object without casting a shadow.

Light linking lets you control the affect a light has on your scene objects on a per-object basis.

Shadow linking allows you to break the casting of shadows from lights on a per-object basis.

Each of these methods is covered in detail below.


Light Linking

The example scene below has a simple lighting setup with only 3 lights: a visible red, green, and blue light that are currently affecting all the objects in the scene.


Example scene with all lights affecting all objects


This all white scene is helpful in interpreting what is happening further down the road when we start introducing some light linking into the scene. As you can see in the image above every object is white due to the red, green, and blue light mixing together. The slight color shifts here and there are simply due to the slightly different light positions. It is important to remember that in all the examples below all 3 lights are always linked to the ground object.






Shadow Linking