Autodesk 62205-051408-9001 User Guide - Page 746

29 Adding Lighting Effects Use lights to add mood, color, and dimension to a 3D composite. You can use the lighting tools to re-create realistic effects or build a fantasy world. About Lighting You can use lighting to add realistic effects and texture to 3D composites. Note: There are no lights in a 2D composite, and therefore no Light controls in the Composite Controls panel. The effect that light has on a layer depends on the surface characteristics of the layer as much as it depends on the type, color, and intensity of the light. When light strikes a layer, it is reflected and it casts shadows in the scene. For example, the behavior of light depends on the opacity, luminosity, and specular level of the layer it strikes-just as real-world light striking a shiny metal surface has a different effect from that striking a rough wooden surface. You can animate all the properties of a light, as well as the surface characteristics of layers, to create dramatic lighting effects. For example, you can animate highlights across the surface of an object by animating the position of the light and the specular level of the object. You can also control how a nearby light spreads across the surface of an object by adjusting the diffusion level of the object. Note: For more information on changing the surface properties of layers, see Chapter 8, "Using Surface Properties''. Ambient Light and Source Light There are two possible kinds of light in a composite: ambient and source. By default, every 3D composite has ambient light that provides a constant amount of light to every visible surface of the layers (front and back sides). Ambient light has no defined origin, so it is not an object in the composite like a source light is. You can modify the ambient light settings in the Timeline via the Global Settings category, or in the Light controls in the Composite Controls panel. However, the settings for ambient light in the Light controls appear alongside the settings for any source lights you may add to the composite. Source light is the light that comes from a controlled light source. For example, camera flashes and spot lights are source lights. You can modify the properties of source lights and animate them over time. You can move, rotate, copy, and paste source lights, target them to layers, and parent them to create groups of lights. There are three types of source lights: Distant, Point, and Spot. Note: If you cannot see the lighting in a composite, make sure the Shading option in the Settings controls is enabled. About Distant Lights Distant source lights project light onto objects as if from an infinite distance. For example, use distant light to simulate sunlight or moonlight. Because the distant light strikes all objects simultaneously, the composite appears evenly lit. The icon for a distant light is a star with rays radiating from it. Distant light icon 730