|Applicable Blender version: 2.68.|
Open a new Blender document. Delete the default cube, and insert the Monkey (Suzanne) instead. Hitto render. You should get something like this.
See how the character’s face—arguably the most important part you usually want to look at—is in shadow? That is absolutely terrible lighting.
In this section, we will look at how to improve the lighting of this scene. The object of the game is not to get rid of all shadows, because flat-lit scenes tend to look pretty boring, too. Instead, we will look at how to make imaginative use of the placement and strength of highlights and shadows, to add interest and realism to the scene.
If you have any experience with photography, a lot of this material should be familiar to you. Lighting in 3D rendering borrows a lot from the accumulated experience that photographers have had with lighting real-world scenes. However, because computer graphics cannot be 100% faithful to the laws of physics, some limitations apply. And also some tricks become possible that are simply not achievable in the real world.
In photography, there are basically two kinds of lighting setups: outdoor and indoor. In the real world, outdoor lighting (at least in daylight) is dominated by the Sun. This is a single, extremely strong light source. But there is also indirect sunlight reflected off other objects, including the sky, and these tend to soften the shadows and even add some colour to them. Outdoor close-up model photo shoots also frequently make use of metal sheets, held up by support crew, to deliberately add more of this indirect reflection and make the lighting of a model more even.
Indoor (studio) lighting setups are commonly described in terms of the number of lights employed, commonly “one-point”, “two-point” or “three-point” for 1, 2 or 3 lights.
In 3D graphics, you can cheat over this outdoor/indoor distinction. After all, the Sun is just another light source you can choose to place in a scene. Instead of metal reflectors, it is usually simpler to just add more lights, even if it is meant to be an outdoor scene. In Blender, the lights themselves need not show up in the render, only their illumination of the scene.
Continuing on from the above example, move the default lamp so it is roughly in the same location as the camera. Now your render should look something like this:
This is similar to the lighting you get when you take a picture on a point-and-shoot or cameraphone with flash enabled: because the light source is close to the lens, you don’t see many shadows (think about it: the parts the light doesn’t reach are close to the parts your vision doesn’t reach), leading to a very flat image. This is why experienced photographers often try to avoid using the flash.
This time I have gone back to the default light position, and added a second light (“fill light”) close to the camera, reducing its strength to 0.5, while the original “key light” stays at 1.0. That way the second light fills in the shadows just enough to make things legible, without flattening out the lighting completely.
The important point is that the key (brightest) light is not at the camera position. That way, the image will contain some interesting shadows.
Now we add a third light, called the “backlight”. This is positioned behind and a little above the model, and serves to accentuate the upper silhouette (particularly the head and shoulders), and make our model stand out from the background. I set its energy to 2.0, to increase the effect. This screenshot shows what should be a good position for this light (it is directly above the green line of the Y-axis). Put it too close to Suzanne, and her bald head will glow a little too brightly. :)
Now the render looks like this. Does the effect look familiar? You should have seen something like it in countless close-ups in film and TV, as well as portraits.
Other Lighting SetupsEdit
Of course, there are countless other ways to light a scene. The above ones are mainly intended for close-ups and portraits. But where there are multiple characters in a scene, or even no characters at all and just the scene, you may want to position multiple lights to draw attention to some parts or characters while playing down other parts.
- Portrait Lighting Setups — a good intro to the different lighting setups commonly used for professional portrait photography.