You can have as many objects as you want in a scene, but until you have light you will not see anything. Everything will cease to have form until there is light. I put together a few images that help show RGB lighting and 3 point lighting technique.
Most think it is objects which gives form to an environment, when really it is the addition of light. I think this is missed because 3D modeling applications automatically add a default light to the scene. To start thinking about light, our class assemble three cameras, one green, one blue, and one red, all pointing to one spot equidistant from each other. The result is shown above. This was a neat exercise. It allowed me to clearly understand blending of light.
Also I wanted to share learning about Three Point Lighting. Three point lighting (here is a tutorial) is a generic technique also used in many instances such as 3D modeling, photography, and even figure drawing sessions. It is called 3 point lighting because the technique uses three lights, a key light, a fill light and a rim light. This exercise helps one think about where lights are placed to give proper definition and form to a scene.
This first image is not 3point lighting system but a basis of comparison because it uses a skylight. Notice how the skylight evenly lights the scene and provides no shadows.
After removing the skylight, we then added the first of the three lights, the key light. A key lights purpose is to be the main light source. This lights is to be placed above the camera and to the left ( ~45-60 degrees). An upper left light source provides the most aesthetically pleasing ( i.e. “accepted” ) source of light.
Next was a fill light. The purpose of the fill light is pretty much in the name, to help “fill” the scene with more light. This light was placed on the opposite side of the camera ( about the same distance as the key light ( ~45-60 degrees), however it can be placed above, below or parallel to the camera. With the fill light try to introduce little to no shadow.
The last light was the rim light, which is placed opposite the camera and behind the subject matter. This light helps to introduce some light to dark areas in the image. Even in the shadows you still want a little light, just to show subtle details.
The renders I provided are a little blown out by the addition of the third light. I encourage following the tutorial in order to learn for yourself. You don’t even need a 3D modeling program, just some objects and three lamps!