Three-point lighting is a technique widely used in traditional photography and cinematography. Its purpose is to properly illuminate a subject in an effective way that is not only pleasing to the eyes but also relatively simple in its approach. By using three separate lights you have complete control on how the subject is illuminated. The world of 3D has grasped onto this lighting technique, and it can be seen in everything from product visualizations to character busts and more. It has quickly become the go-to lighting technique for many 3D scenes because great lighting results can be achieved relatively quickly. Three-point lighting is great for creating a studio type lighting effect, if you are creating a still image or if you need to illuminate a single subject or product.
The most common way to achieve proper three-point lighting is by using three different spot lights in the scene. Setting up each light the correct way will allow the subject to be illuminated without deep shadows and be seen properly in the camera view. The first and most important light is the key light. Like the name suggests, this light is vital when establishing the overall lighting for the scene. It should have the most intensity out of the three lights and should highlight the form and dimension of the subject. The key light is typically set up to the right of the camera at a 45 degree angle. Once the key light has been properly set up, then the fill light should be created. The fill light’s purpose is to fill in the deep shadows that are inevitably cast onto the subject by the key light. The fill light is usually set up opposite of the key light. The last spot light used is the rim light (sometimes referred to as the back light). This has the least illumination effects to the subject because it is typically placed directly behind the subject, facing the camera. The rim lights purpose is to add a very slight glow to the back of the character. If you were to hide the key and fill light, you would see that the subject is darkened all around, except a small light around the edges.