How to use multiple lighting models?

From the documentation I’ve found multiple lighting models (two sets of objects sharing the same general physical space, two sets of lights) isn’t supported. My aims are to have a realistically (or otherwise) shaded set of models and a second set of models - 3d UI objects embedded in the scene - that have a custom lighting model, probably very simple.

My guess is that to do this I’d need to:

  1. Mask the UI objects so I can post process them with their custom lighting model
  2. Prevent the UI objects from receiving lighting
  3. Create a post process material that shades the UI objects

An extra caveat is that the UI objects are sometimes translucent and the background scene will need to be coherently lit despite not being top trumps in the depth scene.

Or I just keep hacking away and perhaps find a way to use emissive color in dark scenes.

Any suggestions welcome!

Caveat: Needs to work on iOS and Andriod devices.


Two questions for graphics types.

  1. Can I apply a post process mask on certain objects that an iphone 5 post process pass can pick up?
  2. If so how - is the “custom depth” approach the only way given I just need 1 bit?

I guess another option is to keep everything in the emissive pass and bake detail into textures.