This command opens the Add Default Lights To Scene dialog, which provides options that let you convert the default scene lighting into actual light objects.
The default lighting for viewports consists of a key light, positioned in front and to the left of the scene, which behaves as an omni light..
This command is unavailable unless you use the Viewport Configuration dialog to configure the active viewport to use two lights. When viewports use two lights, and you invoke this command, the lights are added to the scene as omni lights. You can add either the key light, the fill light, or both.
Two default lights are placed opposite to each other.
A, the key light is in front of the object, on the upper left side, while B, the fill light is behind on the lower right side.
You can add either the key light, the fill light, or both. The omni light objects have the names DefaultKeyLight and DefaultFillLight.
If you have already added one or both default lights, a warning prompts you to rename or delete the previous default light object before you add another.
To add the default lights as objects:
3ds Max opens the General viewport label menu.
When on, adds the default key light to the scene. The key light is in front of the scene and to the left. The key light becomes an omni light with the name, DefaultKeyLight. Default=on.
When on, adds the default fill light to the scene. The fill light is behind the scene and to the right. The fill light becomes an omni light with the name, DefaultFillLight. Default=on.