Copyright Goodheart-Willcox Co., Inc. 454 AutoCAD and Its Applications—Advanced PROFESSIONAL TIP PROFESSIONAL TIP Highlights can be seen everywhere. Look around you right now at edges and inclined surfaces. The diffuse color of the surface typically has little to do with the color of the highlight. The color of the light source usually determines the predominant highlight color. Most highlights are white or near white because most light sources are white or nearly white. However, highlights in the interior of a home may have a yellow cast to them because incandescent light bulbs generally cast yellow light. Compact fl uores- cent lights cast a slightly different color, although many are designed to cast the same color as an incandescent bulb. Outside with a clear sky and bright sun, highlights may have a slight blue cast. Keep these points in mind when creating your own materials. These small details are what make a scene realistic. Refl ectivity Category Refl ectivity is a measure of how much light is bounced off the surface. There are two basic property settings for refl ectivity, Direct and Oblique. See Figure 17-12. The Direct property controls how much light is refl ected back for surfaces that are more or less facing the camera. The Oblique property controls how much light is refl ected back when the surface is at an angle to the camera. Each property has a slider/text box that controls the amount of refl ectivity. No refl ections are created with a setting of 0. The maximum refl ections are created with a setting of 100. Object color, lighting, surroundings, and other factors also determine just how refl ective a material appears in the scene. The buttons to the right of the text boxes allow you to add a texture or image to control the refl ection. The white areas of the texture or image have a refl ection. The black areas do not have a refl ection. The degree of refl ectivity varies for gray areas and the grayscale values of colors. Direct setting Oblique setting Figure 17-12. Setting the reflectivity for a material.