Making a completely transparent object a light source? Down below is a rendered image of what I'm modelling (please excuse the fire flies). There is actually a RED spot light shining into the cube, and the refracted light shining into the cube is shined onto a jellyfish. The problem is that the light refracted by the cube and onto the jellyfish is WHITE not RED.



What I want to do is make a transparent material, like the the glass cube in the rendered image, that refracts so much light and color, in this case the red light, from its environment that is basically acts as a light source while still being completely transparent.

How would I go about doing this?

Here are the nodes that I used.
You can just add an object as an emission and disable it's view in the render;