Due to the limitations of our DLC pipeline, we could not bake lighting in-engine. I wanted an easy way to author the color and lighting of a scene in Unity without using real-time lighting or painting in lots of custom textures.
To achieve this, I created a simple shader that would set a "lighting" texture to use world space coordinates. You could manipulate the texture's scale and position in the world to align it perfectly with the set. This texture was then multiplied by the grayscale "base" texture of the objects in the scene.
By taking this approach, meshes could be dragged around in 3D space and still retain the illusion of having lighting information. The lighting texture itself could be as small as 128x128 and the scene was effectively unlit, making it nice and light for mobile platforms, while still working within the restrictions of our DLC system.
Here is an example of dragging the U-offset value of the "lighting" texture on the grass and ground.