There are three Light ModesA Light property that defines the use of the Light. Can be set to Realtime, Baked and Mixed. More info
See in Glossary available in the Light Inspector:
It is important to note that the mode of a light is only relevant if the Baked Global Illumination system is enabled. If you do not use any global illumination system or only use Enlighten Realtime Global Illumination system, then all Baked and Mixed lights will behave as though their Mode property was set to Realtime.
These are also known as Realtime Lights.
Unity performs the lighting calculations for Realtime Lights at runtime, once per frame. You can change the properties of Realtime Lights at runtime to create effects such as flickering light bulbs, or a torch being carried through a dark room.
Realtime Lights are useful for lighting and casting shadows on characters or moveable geometry.
These are also known as Mixed Lights.
Mixed Lights combine elements of both real-time and baked lighting. You can use Mixed Lights to combine dynamic shadows with baked lighting from the same light source, or when you want a light to contribute direct real-time lighting and baked indirect lighting.
To use Mixed Lights, you must first understand the benefits and limitations of Realtime LightsLight components whose Mode property is set to Realtime. Unity calculates and updates the lighting of Realtime Lights every frame at runtime. No Realtime Lights are precomputed. More info
See in Glossary and Baked LightsLight components whose Mode property is set to Baked. Unity pre-calculates the illumination from Baked Lights before runtime, and does not include them in any runtime lighting calculations. More info
See in Glossary.
Note that if you disable Baked Global Illumination in your Scene, Unity forces Mixed Lights to behave as though you set their Mode to Realtime. When this happens, Unity displays a warning on the Light component 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.
These are also known as Baked Lights.
Unity performs the calculations for Baked Lights in the Unity Editor, and saves the results to disk as lighting data. This process is called baking. At runtime, Unity loads the baked lighting data, and uses it to light the Scene. Because the complex calculations are performed in advance, Baked Lights reduce shading cost at runtime, and reduce the rendering cost of shadows.
Baked Lights are useful for lighting things that won’t change at runtime, such as scenery.
Note that if you disable Baked Global Illumination in your Scene, Unity forces Baked Lights to behave as though you set their Mode to Realtime. When this happens, Unity displays a warning on the Light component Inspector.