As a photo guru said to me once, “Look at the light.” Figure out what “this thing is glowing” means to you and to the shot. For instance, it might simply be a different materal, with a different color, more specularity and so on.
Often, part of what says to your eye, “this thing is glowing,” is that light is falling onto nearby objects. Just as Alfred Hitchcock famously put a light-bulb into a glass of milk, you can put lamps into, or near to, things that should be “emitting light,” to provide the shine on nearby objects. In CG, there are a few important tricks that you can use:
- Remember that, no matter where the lamp is, you can’t “see” it. Unlike a real lamp or light bulb, you only see the light that it produces when it bounces off something. So, it can be “in plain sight.”
- You can control what the light from the lamp does, and doesn’t, “see.” For example, you can designate that a light will only “shine on” things in certain layers (the group-of-buttons …), and that it therefore will “shine right through” objects that would otherwise block the light.
- Don’t bother trying to model “real physics” here. Pay attention, instead, to what the presence or the absence of the lamp does to the light … to the illumination of nearby objects, to changes in color and saturation (e.g. the visual cues that tell you that a window “contains glass”). Consider what are the most important cues and which ones maybe don’t really matter.
- Get to know Blender’s node-based compositor. Sometimes, a “realistic looking scene” is, technically speaking, “anything but.” The compositor will give you absolute control over the lighting within a scene, although at a certain learning-curve price. It is “the ultimate digital darkroom,” and, as Ansel Adams once put it, “a picture is captured in the camera, but made in the darkroom.”