LOD and Realtime GI

Read this page before you use Realtime Global IlluminationA group of techniques that model both direct and indirect lighting to provide realistic lighting results. Unity has two global illumination systems that combine direct and indirect lighting.: Baked Global Illumination, and Realtime Global Illumination.
See in Glossary (GI) on models which use the LOD (level of detail) feature.

When you use Unity’s LODThe Level Of Detail (LOD) technique is an optimization that reduces the number of triangles that Unity has to render for a GameObject when its distance from the Camera increases. More info
See in Glossary system in a SceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary with baked lighting and Realtime GI, the system lights the most detailed model out of the LOD Group as if it is a regular static model. It uses lightmapsA pre-rendered texture that contains the effects of light sources on static objects in the scene. Lightmaps are overlaid on top of scene geometry to create the effect of lighting. More info
See in Glossary for direct and indirect lighting, and separate lightmaps for Realtime GI.

To allow the baking system to produce real-time or baked lightmaps, select the GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary you want to affect, view its Renderer component in the InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
See in Glossary window, and check that Contribute Global Illumination is enabled.

For lower LODs in an LOD GroupA component to manage level of detail (LOD) for GameObjects. More info
See in Glossary, you can only combine baked lightmaps with Realtime GI from Light Probes or Light Probe Proxy VolumesA component that allows you to use more lighting information for large dynamic GameObjects that cannot use baked lightmaps (for example, large Particle Systems or skinned Meshes). More info
See in Glossary, which you must place around the LOD Group.

Whenever you use Realtime GI, the Renderer enables the Light ProbesLight probes store information about how light passes through space in your scene. A collection of light probes arranged within a given space can improve lighting on moving objects and static LOD scenery within that space. More info
See in Glossary option for the lower LODs, even if you enable Contribute Global Illumination.

• 2019–08–01 Page amended

• Added Realtime Global Illumination in 2017.3 NewIn20173