Copyright Goodheart-Willcox Co., Inc. Chapter 17 Materials in AutoCAD 459 for typical materials. Some of these choices include Dim Glow, LED Panel, and Cell Phone Screen. The Color Temperature property determines the warmth or coolness value of the color. The value is expressed as degrees Kelvin. Candles and incandescent bulbs are warm. Fluorescent lights and TV screens are cool. The drop-down list gives you choices for typical objects with different color temperatures, but you can enter a value directly in the text box. Bump Category The Bump category contains settings for making some areas of the material appear raised and other areas depressed, Figure 17-21. The image or texture used for this effect is called a bump map. The black, white, and grayscale values of the map are used to determine raised and depressed areas. Dark areas of the map appear raised and light areas appear depressed. For example, to show the texture of a brick wall, you could physically model the grooves into the wall. This would take a lot of time to model and would immensely increase the rendering time because of the increased complexity of the geometry. Using the properties in the Bump category is an easier and more effi cient way to accomplish the same task. Figure 17-22 shows a bump map used to represent an embossed stamp on a metal case. To apply an image as a bump map, pick the Image property swatch to display a standard open dialog box. To apply a texture as a bump map, pick the button next to the edit box to display a drop-down list. The Amount property determines the relative height of the bump pattern. A setting of 0 results in a fl at material, or no bumps. A setting of 1000 creates the maximum difference between low and high areas of the pattern. Pick to select a texture Set the amount Pick to select an image Figure 17-21. Making bump settings for a material.