Autodesk 12812-051462-9011 User Guide 3 - Page 224

surface. When you render an object with a bump-mapped material, lighter (whiter) areas of the map appear to be raised, and darker (blacker) areas appear to be low. NOTE The effect of a bump map is not previewed in viewports. You must render the scene to see the bump effect. Bump mapping uses the intensity of the map to affect the surface of the material. In this case, the intensity affects the apparent bumpiness of the surface: white areas protrude, and black areas recede. Use bump maps when you want to take the smoothness off a surface, or to create an embossed look. Keep in mind, however, that the depth effect of a bump map is limited. If you want extreme depth in a surface, you should use modeling techniques instead. For example, the Displace modifier on page 1344 pushes surfaces or faces in and out based on the intensity of a bitmap image. (Displacement mapping on page 5487 is another way to do emboss a surface.) Grayscale images can make effective bump maps. Maps that shade between white and black generally work better than maps with hard edges between the white and black areas. The bump map Amount adjusts the degree of bumpiness. Higher values render as higher relief; low values render as low relief. The bumps are a simulation created by perturbing face normals before the object is rendered. Because of this, bumps don't appear on the silhouette of bump-mapped objects. TIP If you render a bump-mapped material and notice aliasing in the highlights, try turning on supersampling on page 5381 and rendering again. NOTE Most controls on the Output rollout on page 5774 don't affect bump mapping. Only the Invert toggle is considered; it reverses the direction of the bumps. Procedures To assign a bump map: 1 Click the Map button labeled Bump. The Material/Map Browser on page 5290 is displayed. 2 Choose from the list of map types on page 5767, and then click OK. The Material Editor is now at the map level, and displays controls for the map parameters. Standard Material | 5479