A damp, foggy, misty night. These words can't help but stir the imagination. The atmosphere they create lays a backdrop to many a story: horror, suspense, mystery, or drama. Perhaps monsters lurk around corners, silent killers stalk their targets, or shady deals go on in mysterious alleyways.
Although we will be lighting this environment with a relatively simple lighting solution and not require complete accuracy, it's still important to carefully set up the scene to ensure quick rendering and optimal settings.
Our task is to light and render the scene in this manner, creating the same emotion and depth as those first four words evoke. As with any project that demands a near photoreal depiction of a real life phenomena the key to the initial stages is research.
After collecting hundreds of images that show these conditions, we can start to break them down into key elements for reference. The main images you should look for are:
• Fog, or heavy mist that gets stronger with distance.
• Headlamps or lights that have a halo, or appear blurred and brighter.
• Lights and light rays cast through the mist, creating volumetric effects.
• Tones becoming muted and less colorful.
• Objects in the foreground appearing more silhouetted.
• Low lying mist that silhouettes other objects.
• Light dispersing slowly through the scene, giving a blurred, ghostlike appearance to any objects caught in between.
Now that we know a few of the elements that make up the image, we can start to work out how to achieve these effects in 3D.
We start off with the basic scene, simple textures set up on all objects, and a camera angle.
The scene is not particularly detailed, with all our detail coming from textures, bump maps, and specular maps. This is sufficient because our final image will be just that - an image, and thus we won't require any close ups of certain areas.
Lets jump right in there and place our primary light source. This is the main light contribution for the scene and will be our streetlamp. It's a unique and central feature that will cast some interesting shadows around the scene (Fig.01).
Choose an area light from the Create > Light menu and it will appear at the centre of the scene. Switch to the Transform tool and move the light in place inside the frame of the streetlamp. The direction of the area light will be wrong, so just rotate it to face downward (Fig.02).
Now it's facing downward, we need to turn it into a Mental Ray area light. In the attribute editor of the light, scroll down and find Mental Ray. Click Use Light Shape, then select Sphere from the light. That will let us simulate a round bulb reasonably accurately (Fig.03).