For indoor and local lighting, you will want to add Light objects to your scene. These are GameObjects that are not rendered themselves as meshes but rather emit light in a specific pattern, such as a cone (for example, a Spot light), sphere (for example, a Point light), or unidirectionally (for example, a Directional light). Also, you can specify individual objects to illuminate from their inside by assigning Materials with Emission properties. For more information on designing and using light objects, see the following links:
- Best Practices Guide: Making Believable Visuals: Indoor and local lighting—https://docs.unity3d.com/Manual/BestPracticeMakingBelievableVisuals7.html
- Unity Manual: Types of light— https://docs.unity3d.com/Manual/Lighting.html
- Emission— https://docs.unity3d.com/Manual/StandardShaderMaterialParameterEmission...