Building the scene
Global Illumination & sunlight
There are several ways to simulate this effect. For most of my scenes I use a dome of infite lights. More than 50 lights is no exeption. Sometimes with shadow map, other times with raytrace shadows. Depends on the type of scenery. For this scene I used a dome of spotlights, not many, only 25 spotlights were used in this dome enough to create that typical ambient kind of light with it's soft shadows. All lights are pointing towards the center of the scene and all have the same values exept for the shadowmap sharpness. The lights on top have high sharpness, the others low sharpness.
You can experiment with giving each spot it's own color and intensity. It sometimes can add that little bit of extra to achieve realistic illumination of your scene.
This is a cluster of infinite lights simulating the sun on a bright day. But because it's quite a bunch they are set to a low level of intensity. Casting raytrace shadows wich gives that typical sunny day shadow effect.
Why a cluster, pointing slightly in different directions? This wil result in a combination of sharp and soft shadows. You can do this with spotlights aswell but infinite lights are best suitable for sunlight and they also give better shadow results.
These are infinite lights that are added for ambient lighting. You could skip these if you have added some ambient glow to your objects. I believe to have better control to give no ambient glow to the objects. Instead I add this effect with these infinite lights set to a very, very low intensity and NO shadow casting.
Point them in straight directions, play around with color settings, that's all.
The spotlight mentioned earlier.
An array of spotlights to simulate light that bounce of from the shiny adapters. Shadow casting off and very low intensity. Just enough to slightly illuminate the edge of the top planks.