Lighting plays an integral part in Computer Graphics (CG) imagery. In the real world, whatever we see, our visual interpretation of things depends upon the way light interacts with the environment around us. Similarly, how we perceive a 3D space or scene depends on
how the lighting has been set-up.
Lighting is one of the most important parts in composing the scene and maintaining overall quality of the image. Lighting helps
– establish the mood, depth and volume in 3D space
– direct the viewer’s eye to the object in focus
– accentuate the look and feel of different materials used on 3D objects
– maintain continuity with different spaces of the same project
All the above mentioned points resonate with these four images.
There are two broad divisions: Natural Lighting & Artificial Lighting Natural light is always present in any scene unless we want to create a space where there are no windows. It makes the space look bigger & it blends the exterior with the interior, which in turn cause the space to look more organic and welcoming. It is the first step of setting up a believable lighting rig.
The Sun and the Skylight (scattered light in atmosphere) are sources of natural light. The color, nature (soft or harsh) and intensity of natural light is dependant on time of the day and the weather conditions.
Artificial light is produced by man-made objects like incandescent bulbs, fluorescent tubes and LEDs. Artificial lighting has many applications such as accentuating areas or objects of interest, light up lamps and luminaires etc.
For better understanding of these concepts, let’s take a look at an example of a reading corner:
In this scene, the window on the left act as the primary source of Natural Light. As a result, light blue skylight is scattered in the space and the room is illuminated.
Artificial Lights are added to the previous light rig for floor lamp’s glow. This is also a good example of task lighting, in which artificial lights give purpose and aesthetic to an object, in this case, the floor lamp (which also acts as a reading light).
Further, when the warm artificial light (right) blends with the cool natural light (left), it produces a nice contrast in the image and causes the chair to be highlighted.
In this example, a few key things were kept in check while creating the light rig:
As we noticed, the skylight and floor lamp’s glow blended well thanks to the choice of complementary colors. Light blue and warm yellow for natural and artificial light respectively.
We have to be careful with the intensity of lights while setting up the scene. Keep the intensity too low, and the scene will end up dark and under-illuminated. On the other hand, if the intensity is too high, certain areas closer to the light source will be burned and end up rendering completely white.
Distribution and Positioning
It is crucial that we do not over-populate our scene with lights. Also, the placement of lights should do justice to the light sources and overall composition. If we do not stick to the right distribution and positioning of lights, it is certain that we will end up with an undesirable result which will be hard to control or tweak.
Maintaining Shadows and Dark Areas
While, lighting the scene, it is imperative that we maintain some shadows and dark areas in our composition, otherwise the scene might end up looking washed out and flat.