3ds Max 2012 Bible - Kelly L. Murdock [340]
FIGURE 30.8
The mental ray Connection rollout in the Material Editor lets you override the default shaders.
The lock icons to the right of the shader buttons are the default shaders used by the Scanline renderer. To select a new shader, simply unlock these shaders by clicking the lock button. If a material is opaque, you can speed up the rendering process by flagging the material as Opaque, using the option at the bottom of the rollout.
If you want to get direct access to the shaders used by mental ray, use the mental ray material type, which presents all the shaders listed in the mental ray Connection rollout.
Using the Autodesk Material Library and the Arch & Design materials
The Autodesk Material Library and the Arch & Design materials are a set of advanced mental ray materials designed for architects to add to buildings and surfaces found in architecture renderings. All of these materials are based on physical properties that are typically found in environments lighted with global illumination. For example, the Satin Varnished Wood template includes slightly blurred reflections and a high glossiness to give it a realistic look.
The materials contained in the Autodesk Material Library are categorized into groups and subgroups. Each material has several parameters allowing you to change the color, glossiness, reflectivity, and so on. The available parameters change based on the selected material.
Many of the Arch & Design materials are already defined and available in the Templates rollout. The available presets include Pearl Finish, Satin Varnished Wood, Glazed Ceramic, Glossy Plastic, Masonry, Leather, Frosted Glass, Translucent Plastic Film, Brushed Metal, and Patterned Copper.
For each template, several rollouts of parameters are available for defining the Diffuse, Reflection, Refraction, Translucency, Anisotropy, Fresnel Reflections, Bumps, and Self-Illumination properties along with a full selection of maps. Figure 30.9 shows a sampling of the available materials.
FIGURE 30.9
The materials in the mental ray Arch & Design collection include a broad set of physical properties.
Within the Special Effects rollout are two specialized options that add to the render realism. Ambient Occlusion lights the scene based on how accessible ambient light is to scene objects. It is a material shader solution and is not based on lights. Areas that face a wall or are blocked by other objects are recessed in shadow. Areas facing the lights are highlighted more. Using the Samples and Max Distance, you can control the contrast of the resulting image. By default, ambient occlusion uses black and gray tones to show occluded areas, but if you enable the Use Color From Other Materials (Exact AO), then the object's diffuse color is reflected into the occluded areas. Figure 30.10 shows an example of Ambient Occlusion.
Note
The Nitrous display drivers make ambient occlusion effects visible in the viewports.
The other useful special effect option is Round Corners. When you apply this option to a mechanical object, the object's edge is rounded so the light source highlights the edge, but no change is made to the object's geometry. This creates a realistic soft edge without the time or extra polygons to create it using geometry.
Using the Self Illumination (Glow) rollout, you can make a material act as a light source to the scene. This rollout includes presets for photometric properties based on real-world values such as degrees Kelvin.
FIGURE 30.10
Ambient Occlusion lets you light the scene by controlling the ambient light that gets bounced around the scene.
Using the Car Paint material
When cars are painted in the factory, the paint is composed of two layers that give the car its unique look. The undercoat is called the flake layer, and it shines through the top layer. The mental ray Car Paint material includes settings for defining both of these layers. Figure 30.11 shows a car