3ds Max 9 Bible

Materials are used to dress, color, and paint objects. Just as materials in real life can be described as scaly, soft, smooth, opaque, or blue, materials applied to 3D objects can mimic properties such as color, texture, transparency, shininess, and so on. In this chapter, you learn the basics of working with materials and all the features of the Material Editor.

Understanding Material Properties

Before jumping into the Material Editor, let's take a close look at the type of material properties that you will deal with. Understanding these properties will help you as you begin to create new materials.

Up until now, the only material property that has been applied to an object has been the default object color, randomly assigned by Max. The Material Editor can add a whole new level of realism using materials that simulate many different types of physical properties.

Colors

Color is probably the simplest material property and the easiest to identify. However, unlike the object color defined in the Create and Modify panels, there isn't a single color swatch that controls an object's color.

Consider a basket of shiny red apples. When you shine a bright blue spotlight on them, all the apples turn purple. So, even if the apples are assigned a red material, the final color in the image might be very different.

Within the Material Editor are several different color swatches that control different aspects of the object's color. The following list describes the types of color swatches that are available for simple materials:

• Ambient: Defines an overall background lighting that affects all objects in the scene, including the color of the object when it is in the shadows. This color can be locked to the Diffuse color so that they are changed together.

• Diffuse: The surface color of the object in normal, full, white light. The normal color of an object is typically defined by its Diffuse color.

• Specular: The color of the highlights where the light is focused on the surface of a shiny material.

• Self-Illumination: The color that the object glows from within. This color takes over any shadows on the object.

• Filter: The transmitted color caused by light shining through a transparent object.

• Reflect: The color reflected by a raytrace material to other objects in the scene.

• Luminosity: Causes an object to glow with the defined color. It is similar to Self-Illumination color but can be independent of the Diffuse color.

If you ask someone the color of an object, he or she would respond by identifying the Diffuse color, but all these properties play an important part in bringing a sense of realism to the material. Try applying very different, bright materials to each of these color swatches and notice the results. This gives a sense of the contribution of each color.

Opacity and transparency

Opaque objects are objects that you cannot see through, such as rocks and trees. Transparent objects, on the other hand, are objects that you can see through, like glass and clear plastic. Max's materials include several controls for adjusting these properties, including Opacity and several Transparency controls.

Opacity is the amount that an object refuses to allow light to pass through it. It is the opposite of transparency and is typically measured as a percentage. An object with 0 percent opacity is completely transparent, and an object with an opacity of 100 percent doesn't let any light through.

Transparency is the amount of light that is allowed to pass through an object. Because this is the opposite of opacity, transparency can be defined by the opacity value. Several options enable you to control transparency, including Falloff, Amount, and Type. These options are discussed later in this chapter.

Reflection and refraction

A reflection is what you see when you look in the mirror. Shiny objects reflect their surroundings. By defining a material's reflection values, you can control how much it reflects its surroundings. A mirror, for example, reflects everything, but a rock won't reflect at all.

Reflection Dimming controls how much of the original reflection is lost as the surroundings are reflected within the scene.

Refraction is the bending of light as it moves through a transparent material. The amount of refraction that a material produces is expressed as a value called the Index of Refraction. The Index of Refraction is the amount that light bends as it goes through a transparent object. For example, a diamond bends light more than a glass of water, so it has a higher Index of Refraction value. The default Index of Refraction value is 1.0 for objects that don't bend light at all. Water has a value of 1.3, glass a value of around 1.5, and solid crystal a value of around 2.0.

Shininess and specular highlights

Shiny objects, such as polished metal or clean windows, include highlights where the lights reflect off their surfaces. These highlights are called specular highlights and are determined by the Specular settings. These settings include Specular Level, Glossiness, and Soften values.

The Specular Level is a setting for the intensity of the highlight. The Glossiness determines the size of the highlight: Higher Glossiness values result in a smaller highlight. The Soften value thins the highlight by lowering its intensity and increasing its size.

A rough material has the opposite properties of a shiny material and almost no highlights. The Roughness property sets how quickly the Diffuse color blends with the Ambient color. Cloth and fabric materials have a high Roughness value; plastic and metal Roughness values are small.

Other properties

Max uses several miscellaneous properties to help define standard materials, including properties such as Diffuse Level and Metalness.

The Diffuse Level property controls the brightness of the Diffuse color. Decreasing this value darkens the material without affecting the specular highlights. The Metalness property controls the metallic look of the material. Some properties are available only for certain material types.