Written by Olivier Saraja (olivier_at_linuxgraphic.org)
English version
A few parameters are common to all of the light systems, and will be explained now.
Because the scenes can be heavily enhanced by complex and subtle lightings, it would always be a good idea to give each light a different name . The Name field is a convenient way to sum up the properties of the light system, and this is generally the case with each objects in any kpovmodeler's scene.
Location should be self-explanatory but is very important: the y componant could produce very classical shadows if set high in the sky, or could produce long and stretched shadows (a very dramatic effect easy to achieve) if set low on the horizon, as during dusk or dawn. The x and z componants are equally important because they will state if the objects of the scene are darkened by their own shadows if the light radiates from the background, or are largely illuminated if the light originates from the foreground. In fact, it is always a good idea to make multiple rendering tests with varying location parameters, as interesting and surprising results can arise by experimentation.
The Color of the light is also an important parameter of the light system. While playing with Ambiant Light in the general settings could be more straightforward, subtle colors induced by soft lights could produce very dramatic results. The following picture illustrates perfectly what has been said here. The light source is low on the horizon, which produces very stretched shadows. The whole scene is slightly tainted in orange. The combination of both gives a dusky atmosphere.
Of course, the choice of color is key to the suggestion of an environment, and it could be subdivided into two categories: cold and warm colors. For example, a cold blue color could be choosen to enhance a polar landscape or an ice desert, while a green color will be perfect for a scene located in a swamp, a deep forest or even underwater. With the same goals in mind, warm colors like yellow could be helpful for sunny afternoons, like a paradisiac beach or a desert scene; an orange lighting could suggest either a bonfire or a sunset. Neutral colors can also help with specific scenes: in fact, when you don't know what should be the feeling or the mood of the scene you're working on, always start with the standard white light. Moreover, white light is particularly suited to scenes only lit by the moon and/or the stars; on the other side, light greys will help depicting dull, dusty and mourn worlds if used properly. Choice of color is capital, as it can truly induce feelings: what about a subtle redish light for the background of a battle scene, or a light pink color for a romantic scene? Choice is yours, but always remember to experiment and to try something new each time, as interesting situations could arise.
But now, let's pay attention to the specifics of each light sub-systems.