Autodesk 12812-051462-9011 User Guide 3 - Page 339

How glossy is the material? Are reflections clear or blurry? Are they strong or weak? ■ For clear, fairly strong reflections, keep Reflection Glossiness at 1.0. ■ For slightly blurry but strong reflections, set a lower Reflection Glossiness value. If performance becomes an issue try turning on Fast (interpolate). ■ For slightly blurry but also very weak reflections, you can "cheat" by applying a lower Reflection Glossiness value for broader highlights while setting Reflection Glossy Samples to 0. This shoots only one mirror ray for reflections, but if they are very weak, the viewer can often not really tell. ■ For moderately blurry surfaces, set an even lower Reflection Glossiness value and maybe increase the Reflection Glossy Samples value. Again, for improved performance turn on Fast (interpolate). ■ For extremely blurry surfaces or surfaces with very weak reflections, try turning on Highlights+FG Only. A typical wooden floor could use Reflection Glossiness of 0.5, Reflection Glossy Samples of 16, Reflectivity of 0.75, a nice wood texture for Diffuse Color, perhaps a slight bump map. If bumpiness should appear only in the lacquer layer, turn on Special Purpose Maps rollout > Do Not Apply Bumps To The Diffuse Shading. Linoleum flooring could use the same settings but with a different texture and bump map, and probably with slightly lower Reflectivity and Reflection Glossiness values. Ceramics Ceramic materials are glazed; that is, they're covered by a thin layer of transparent material. They follow rules similar to the general materials mentioned above, but set the BRDF method on page 5557 to By IOR (fresnel reflections) and set IOR to about 1.4 and Reflectivity to 1.0. Set the Diffuse Color to a suitable texture or color, such as white for white bathroom tiles. Stone Materials A stone object usually has a fairly matte finish, or has reflections that are so blurry they are nearly diffuse. You can simulate the "powdery" character of stone with the Diffuse Roughness parameter; try 0.5 as a starting point. Porous stone such as brick would have a higher value. 5594 | Chapter 19 Material Editor, Materials, and Maps