How to Use Light Linking in Blender

Light linking is a powerful rendering feature that allows artists to selectively choose which objects in a 3D scene are illuminated by specific light sources, overriding standard real-world physics for enhanced artistic control. Introduced natively in Blender 4.0 for the Cycles render engine, light linking makes it easy to isolate lighting effects, create distinct character rim lights, or prevent background blowouts without complex compositing workarounds. This guide explains what light linking is and provides a straightforward, step-by-step process for configuring both light and shadow linking in Blender.

What Is Light Linking?

In realistic rendering, a light illuminates every object within its path and casts shadows accordingly. Light linking breaks this physical rule by allowing you to designate specific receiver objects for a given light.

Blender supports two types of linking:

  • Light Linking: Determines which objects are illuminated by a light.
  • Shadow Linking: Determines which objects act as shadow blockers (casters) for a light.

Note: Light and shadow linking are currently supported exclusively in the Cycles render engine.

Step-by-Step: How to Configure Light Linking

1. Set the Render Engine to Cycles

  1. Open the Render Properties tab in the Properties Editor.
  2. Set the Render Engine to Cycles.

2. Access the Light Linking Panel

  1. Select the light source (Point, Sun, Spot, Area, or a mesh with an Emission shader) in the viewport or Outliner.
  2. Go to the Object Data Properties (green lightbulb icon) or Object Properties (orange square icon).
  3. Expand the Shading panel and locate Light Linking.

3. Assign Receiver Objects

  1. Click the New button under the Light Linking section to create a light linking collection.
  2. Add objects to this collection using one of the following methods:
    • Drag and Drop: Drag objects directly from the Outliner into the Light Linking list.
    • Add Object: Click the eyedropper tool or use the collection selector within the panel to assign objects or entire collections.

4. Set Include or Exclude Modes

By default, adding an object makes it the only object illuminated by that light (Include mode). You can change this behavior using the state icon next to the object in the list:

  • Include (White Icon): The light only affects this object.
  • Exclude (Minus/Dark Icon): The light illuminates everything except this object.

How to Configure Shadow Linking

Shadow linking works identically to light linking, but controls which objects cast shadows from a specific light source.

  1. Select your light source.
  2. Under Object Properties > Shading, navigate to the Shadow Linking panel.
  3. Click New to create a shadow linking collection.
  4. Drag and drop objects from the Outliner into the list.
  5. Set the mode to Include (only these objects cast shadows from this light) or Exclude (these objects will not cast shadows from this light).

Managing Light Linking via the Outliner

You can also manage light linking globally using the Outliner editor:

  1. Change the Outliner display mode to Light Linking via the top-left dropdown in the Outliner.
  2. Select any light to view and manage its assigned receiver objects directly in the hierarchy.