Copyright Goodheart-Willcox Co., Inc. Chapter 18 Lighting 491 illumination, such as the illumination you would encounter in an offi ce setting. The distance of the objects in the scene to the distant light has no effect on the intensity of the illumination. Distant lights do not attenuate. A distant light can also be used to simulate sunlight without having to set up a time and location. However, the light must be manually moved to change the illumination effect. NOTE NOTE When creating a distant light, you will receive a warning to the effect that photometric distant lights may overexpose the scene. Your choices are to disable or allow distant lights. If you choose to continue to place the distant light and the scene becomes washed-out with light, adjust the exposure as previously discussed. The DISTANTLIGHT or LIGHT command is used to create a distant light. You are fi rst prompted to specify the direction from which the light is originating or to enter the Vector option. If you pick a point, it is the location of the light. Next, you are prompted to specify the point to which the light is pointing. This is simply the location where the light is aimed. If you enter the Vector option instead of picking a “from” point, you must type the endpoint coordinates (in WCS units) of the direction vector. The light will point from the WCS origin to the entered endpoint. This option is not often used. After the light location and direction are determined, several other options are available. You can name the light, set the intensity, turn the light on or off, and set the light color. AutoCAD provides a default name for new lights based on the type of light and a sequential number, such as Distantlight1, Distantlight2, and so on. It is a good idea to provide a meaningful name for a light. This is especially true if there are other lights in the scene. To rename a light, enter the Name option. Then, type the name of the light and press [Enter]. To set the brightness of the light, enter the Intensity factor option. Then, type a value and press [Enter]. The default value is 1.00. Setting the value to 0.00, in effect, turns off the light. The maximum value depends on the capabilities of your computer. When a light is created, it is on. To turn the light off, enter the Status option. Then, change the setting to Off. DISTANTLIGHT Ribbon Visualize Lights Distant Type DISTANTLIGHT LIGHT Figure 18-10. This example shows the use of a distant light to simulate sunlight shining through a window. Notice how the edges on the shadows of the grill are parallel. A full-color image is provided on the companion website. www.g-wlearning.com/CAD/