Rendering a CG Scene - An Introduction to Computer Graphics for Artists - page 220

Fig. 12.4 In a ray traced image, the primary light ( a ) lights surfaces directly and casts shadows,
but fi ll light is provided by secondary light sources ( b and c )

necessary to make the image ever more clear and clean. A key light , the light used
to set the major color source in a scene, will be placed to light up one side of the still
life. A large refl ector may be placed opposite the key light, and it will have a tint, to
refl ect color into the bottom surfaces of the subjects. Other lights will be added to
illuminate each side of the still life, and each light will be different from the others,
to help defi ne the surface orientation of various parts of each object. An intense rim
light might be added above the scene to outline everything with a white halo; this is
how lighting works. It is about building color and structure into a scene through the
judicious placement and control of light.
After you are comfortable lighting the structure of your subject, you may want to
consider mood. It is possible to light a scene in such a way that with one setup it has
one mood, but after some changes the lights create a completely different impres-
sion. It is precisely because lighting has such a strong effect on a scene that artists
cannot afford to be careless with it. Simply illuminating a scene clearly is not good
enough. If the render requires a mood, regardless of what that mood might be, the
lighting should accentuate it.
A good source of inspiration for mood lighting can be readily found in feature
fi lms, where there is a hundred years of lighting history behind the methods
employed by cinematographers and lighting directors to achieve story nuance
through lighting. Many video game developers incorporate fi lm-styled lighting into
their cut scenes and, sometimes, into real time rendered scene graphics.

12.5.2 Artistic Lighting vs. “Realism”

Most photographers use a wide variety of devices; umbrellas, refl ectors, black
mesh light occlusion frames, fi lters, and gels to change how light affects a scene.