Essentially I want to turn a material into a kind of night-light.
For this character I'm working on, I wanted the crystals on him to glow in the dark... And I got them to glow using various shader nodes. However I can't find a balance that looks bright enough in the dark, and not washed out in the light. So I was thinking perhaps there might be a node that could change the light emission of the crystals depending on the amount of light from external sources.

In truth I don't even know if this is the best way to go about accomplishing what I want... Which is to have only barely semi-transparent crystals that glow brightly in the dark and appear as solid colors with a slight emission [more like my drawing][1] when in the light.

The other question is... will something like that carry over into unity? Because if not I'd rather save myself a lot of heartache.

Here's a picture of what I have so far:
[![enter image description here][2]][2]

[<img src="http://blend-exchange.giantcowfilms.com/embedImage.png?bid=2374" />](http://blend-exchange.giantcowfilms.com/b/2374/)
  [1]: http://i.imgur.com/NNSWwmz.png
  [2]: https://i.stack.imgur.com/tP07f.png