Example – External Lightmapping Tool
The scene before lightmapping
Using the tool you can prepare lightmap texture atlases in Unity, simply by dragging the objects to the chosen lightmap.
Once you’ve chosen your objects press “Export Scene” button
The scene gets exported to 3dsmax (also with Unity lights), where waits for you the External Lightmapping Tool helper.
After you adjust the scene lightning in 3dsmax, this little tool will render and save the lightmap textures to your Unity project directory and apply the lightmaps automatically.
In 3dsmax you can use regular “CTRL+S” shortcut to save your materials and lightning for future changes
After the rendering is complete you can come back to Unity and see the results.
Whenever you’ll have to rebake your scene (objects or lights in scene moved), just press the “Export scene” button again.
The tool will reload the scene in 3dsmax at the point you’ve leaved it at last save.