Preview lightmapping

You can edit 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 and preview changes to 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 and lighting without affecting the baked lightmaps.

To preview, do the following in a scene that uses lightmapping:

1. In the Scene view View Options toolbar, select Debug Draw Mode.
2. Select a Global IlluminationA group of techniques that model both direct and indirect lighting to provide realistic lighting results.
   See in Glossary Draw Mode.
3. In the Lighting Visualization overlay, set Lighting Data to Preview.
4. Make changes to the scene that affect lightmaps.

Unity creates temporary lightmaps and uses them in the Scene viewAn interactive view into the world you are creating. You use the Scene View to select and position scenery, characters, cameras, lights, and all other types of Game Object. More info
See in Glossary. To check the temporary lightmaps, go to the Lighting window and select Baked Lightmaps.

To use the baked lightmaps without your changes, set Lighting Data to Baked.