I'm quite pleased the way the renders turned out. I've been working on this so long that all I see is what has to be fixed, but seeing some renders and hearing some feedback lets me know I'm on the right track*.
*Keep reading for a great continuation of this train based metaphor.
Interestingly (not my opinion, an actual certified Very Interesting Thing™), the rim lighting on the models is actually from the material, not from physical lights. Partially, that's because I think you get more control, but really it's because I've never been able to get completely satisfactory results from trying to set up rim lighting. This setup uses the normal of the faces to determine whether it should be highlighted or not. Here is a (simplified) screenshot of it:
This is a simplified setup, so it just shows the right side rim lighting, if you want other sides of the model to be highlighted, duplicate the 'Normal' and 'ColorRamp' nodes, adjust the normal direction and add them to the other rim nodes with a 'MixRGB' node set to 'Add'.
See I told you it was interesting, and yet you (probably) resisted believing me. Hopefully you will trust me a bit more in future. If not, things are going to get pretty embarrassing for you when I continue to show you Interesting Things™. Let's avert this embarrassment by jumping aboard this train of Trust and riding out this analogy right to the end, together.
Now that all that train business is dealt with I can get on with my work, so that by next week I will be able to show off a new screenshot.
I guess that's the end of the line for this post (THE TRAIN FUN NEVER ENDS).