CHAPTER 9
Advanced Materials

Featuring

•  Understanding Raytrace Materials

•  Applying Maps to a Raytrace Material

•  Creating Matte/Shadow Materials

•  Building Compound Materials

•  Using Materials Features New to R3

•  Understanding Camera Mapping

In Chapter 8, we examined surface shading using the most common material types. In this chapter, you will learn how to shade surfaces with more specialized types of materials, including Raytrace, Matte/Shadow, and five compound material types.

Understanding Raytrace Materials

Materials control how MAX renders surfaces. One of the most beautiful materials, the Raytrace material, simulates photo-realistic, detailed, surface shading effects (see Figure 9.1). It provides in-depth controls for reflection, refraction, transparency, translucency, and fog, as well as many of the basic controls found in the Standard material type.

If you are just going to raytrace a reflection or refraction, you might want to consider using a Raytrace map within a Standard material. The Raytrace map type uses the same raytrace algorithm as the Raytrace material, so it is equally accurate, but the map renders a little bit faster. Another plus is that the Raytrace map gives you extra controls for anti-aliasing and attenuation, while including many of the same mapping and effects features found in Raytrace materials.

In the Material Editor, Raytrace materials have five rollouts of parameter settings: Basic Parameters, Extended Parameters, Raytracer Controls, Maps, and Dynamics Properties.

FIGURE 9.1  Use Raytrace materials to simulate some of nature’s most beautiful lighting effects, such as the refraction of light through glass.

Setting Basic Parameters

Basic parameters for Raytrace materials (shown in Figure 9.2 and listed in interface order in Table 9.1) extend the basic parameters for Standard materials. In Raytrace, Ambient is defined as how much ambient color the shadow will absorb. Setting the Ambient color to white is the same as locking it to the Diffuse color in Standard materials. Diffuse and Specular settings work in the same way as they do in Standard materials.

FIGURE 9.2  Control your Raytrace materials with this rollout.

NOTE Unchecking any of the boxes next to the color swatches in the Basic Parameters rollout accesses a grayscale spinner. This spinner controls how much a parameter affects a material, from zero to 100 percent. Setting this value is the same as checking the box and changing the color swatch from black through the gray values to white. Whether the grayscale spinner or the color swatch is displayed, MAX always uses the visible parameter, and ignores the parameter that is not displayed. (They can indeed differ, and they don’t update one another.)

Transparency works like a combination of Opacity and Filter in a Standard material, except that Transparency settings work in inverse proportion to settings for Opacity. Additional parameters include reflection, index of refraction, environment mapping, and bump mapping. For an example of a raytraced image reflecting the scene around it, see Figure 9.3.

FIGURE 9.3  A raytraced sphere reflecting the scene around it

Creating a Raytraced Reflection

Let’s create a raytraced reflection like the one in Figure 9.3.

1.  Create a plane and assign it a checker mapped material.

2.  Create a sphere that sits on the plane.

3.  Assign an environment map to the background.

4.  Open the Material Editor.

5.  Select an available sample slot.

6.  Click the Type button and select Raytrace from the list of new materials.

7.  In the Raytrace Basic Parameters rollout, change the Reflect color swatch to white or uncheck the box and set the grayscale spinner to 100.

8.  Assign the same bitmap that you used in the scene environment to the local environment map.

9.  Assign the material to the sphere.

10.  Render the scene.

	TIP For faster rendering, turn off Raytrace Refractions in the Raytracer Controls rollout.

	TIP The Reflection parameter overrides the Transparency parameter. If you set the Reflection grayscale spinner to 100% or set the swatch to white, the object will be completely opaque, regardless of its Transparency value.

Setting Extended Parameters

Extended parameters for Raytrace materials (detailed in Table 9.2 and Figure 9.4) allow you to simulate extra light, translucency, and fluorescence, and give you finer control over transparent and reflective surfaces. The Density settings allow you to apply a tint to a transparent material based on the object’s thickness, and to gradually fill the walls of the object with fog so that it becomes opaque.

© 2000, Frol (selection, edition, publication)