The real key to this scene for me was the lighting (which is why I include
shading in this wireframe). I was trying for a "bulb shot" look;
a really long exposure that makes the color of dimmer lights seem richer,
and would overexpose around an ordinary light source. Even though there
are only three apparent light sources (an upstage key light from the bulb
in the alcove, the red signal light from behind the camera, and the blue
fill light further down the track), I also used a variety of little fill
lights near surfaces such as brightly lit alcove walls to simulate reflected
light, and to soften the falloff of the main points. Notice how the geometry
of objects like the ties on the tracks are bevelled: it is almost impossible
to do a really good job of lighting a scene if the edges of things can't
catch a highlight! You've got to plan for their lighting while you model!
This was rendered in the Softimage renderer. I first got the mental ray renderer just as I was finishing the scene. Mental Ray crashed when I sent it this scene (too many materials and textures for the first released version), but I used mr's lens flare function to blow out the area around the light bulb more convincingly, and rendered flares only from mr to composite over softimage rendered frames. In hindsight, I should have used just the glow and not the flares themselves, which start seeming tacky because they are so overused.