MOST 3D PROGRAMS provide default lighting. This may be little more than a spotlight that places a highlight on each object and makes each object cast a shadow.

While not bad for sketchy reference, such lighting is far from realistic and the more time you spend working in 3D, the more dissatisfied you will become with the defaults.

In the real world, light comes from many sources and bounces from object to object. The edges of an object, even those on the undersides, probably have a highlight that helps differentiate it from the background.

Shadows have fall-off. In places shadows crossing will create an area as black as ink, but most shadows are lit around the edges creating soft edges.

Without highlights and shadows, objects blend into the background and become flat.

LIGHTS PICK UP COLOUR.

• Few lamps emit white light. Incandescents glow yellow and fluourescents, often coloured shades of white, blue, or pink, turn scenes green. Our eyes compensate; the camera doesn't, unless we add filters.
• Reflected light picks up colour from objects with which it interacts. Light bounced off a red ball gains a reddish hue. Light on a rainy day reflected off a yellow lily is not the same as sunlight off a pink rose under a blue sky.

How can you make your lighting more realistic?

• Some software has the ability to model real lights. You can add a light to your scene that has exactly the same characterisitics as a 60 watt GE soft light bulb or a 40 watt halogen. When possible, if you need realistic lighting use these lights. They Take longer to render but the effect is worth it.
• Avoid default lights in modeling programs. Add your own lights to the scene to gain control over the angle of the light, the size of the cone of light emanating from the source, the fall-off from the centre of the beam to its edge, how far into the distance the light penetrates, where its light is strongest, how hard the shadows are, etc. There is no better solution than to study the way light interacts in the real world and adjust the parameters in your scene to match.
• To get something more realistic and to add contrast to the scene, add extra lights. This can overlight the scene so that the colours are washed out. But in a good 3D program, there are various ways to use light, usually diffuse, specular and ambient. Apply a second or third light to only the specular. Turn off the diffuse qualities of the light. The objects will gain highlights without overlighting the overall object.
• Make sure your computer output devices (monitors, etc.) are properly calibrated. If your scene is too dark or too bright, don't adjust your monitor to see it better, add or subtract lights.
• Consider changing the colour of the lights you use. By default the lights tend to be white and the shadows are black. In the real world they are often flushed with colour.
• Create highlights to objects by adding lights that act soley on the object your wish to light. Use the exclusion list to prevent the light from interacting with other objects.
• Do the same with shadows. Removing shadows flattens the scene and creates a twilight impression.
• Rendering light takes time, especially if reflections are included. As an alternative, if your software allows it, burn the lights into textures. If your software doesn't allow it, consider making self-illuminated textures in a graphics program. A circle of light with a soft edge (use the gaussian blur) looks like glowing light.
• Increase specularity to pick up sharp highlights and raise the diffuse levels to soften the way light falls on the scene.
• Shine a light into deeply concave objects like cups where light normally bounces around providing a sense of volume. Then add volumetric effects like smoke, to simulate steam rising from a cup.
• Lighting a virtual scene reflects similar issues to lighting a studio or the theatre. Read books on lighting from both these professions. Think about where you want viewers to look and add a subtle spotlight. Let the background disappear into darkness to highlight the foreground subject, or direct the eye to something behind the scene with a small spot.
• Save deep shadows for murky moments. While they are often used to obscure erors, in the real world the only place you find 100% is under a rock in themiddle of the night
• Use luminosity maps to make textures self-illuminated and cut ack on the use of real lights that take ages to render
• Bake the lights into the textures.
• While you're at it, where is the light source? What is natural for the scene. If it's evening and outdoors, the light is probably meant to come from a streetlamp, high above the characters at walking along the road. So your key lights should be high as well. If it's broad daylight, the sun is high overhead, but the intense light bounces off every surface and there should be light coming at your objects from many sides, and few shadows.
• Back lights are a traditional addition to a scene to lighten the shadows behind your objects. It will reduce the contrast but provide slight highlights to separate the object from its background.