Page 565 - Kitab3DsMax

Chapter 18: Creating Compound Materials and Using Material Modifiers

The parameters for this modifier can be set to assign material IDs randomly with the Random Distribution
option or according to a desired Frequency. The ID Count is the minimum number of material IDs to use.
You can specify the percentage of each ID to use in the fields under the List Frequency option. The Seed
option alters the randomness of the materials.

Tutorial: Creating random marquee lights with the
MaterialByElement modifier

The MaterialByElement modifier enables you to change material IDs randomly. In this tutorial, you repro-
duce the effect of lights randomly turning a marquee on and off by using the Multi/Sub-Object material
together with the MaterialByElement modifier.
To create a randomly lighted marquee, follow these steps:
1. Open the Marquee Lights.max file from the Chap 18 directory on the DVD.
This file includes some text displayed on a rectangular object surrounded by spheres that repre-
sent lights.
2. Open the Material Editor and double-click the Multi/Sub-Object material from the Material/Map
Browser. Give the material the name Random Lights.
3. In the Multi/Sub-Object Basic Parameters rollout, click the Set Number button and change its
value to 2. Then click the Material 1 button, and in the Material name field give the material the
name Light On. Set the Diffuse color to yellow and Self-Illumination to yellow. Then click again
on the main material node.
4. Name the second material Light Off, and select a gray Diffuse color. Then click the Multi/Sub-
Object material node.
5. Select all the spheres, and click the Assign Material to Selection button to assign the material to
the spheres.
6. With all the spheres selected, open the Modify panel and select the MaterialByElement modifier
from the Modifier List drop-down list. In the Parameters rollout, select the Random Distribution
option and set the ID Count to 2.
Figure 18.7 shows the marquee with its random lights. (I’ve always wanted to see my name in lights!)
Disp Approx and Displace Mesh modifiers
You can change the geometry of an object in several ways using a bitmap. One way is to use the Displace
modifier (found in the Modifiers ➪ Parametric Deformers menu). The Displace modifier lets you specify a
bitmap and a map to use to alter the object’s geometry. Black areas on the bitmap are left unmoved, gray
areas are indented, and white areas are indented a greater distance. Several controls are available for specify-
ing how the image is mapped to the object and how it tiles, and buttons are available for setting its align-
ment, including Fit, Center, Bitmap Fit, Normal Align, View Align, Region Fit, Reset, and Acquire.
Another way to displace geometry with a bitmap is to use a displacement map. Displacement maps can be
applied directly to Editable Poly and Mesh, NURBS, and Patch objects. If you want to apply a displacement
map to another object type, such as a primitive, you first need to apply the Modifiers ➪ Surface ➪ Disp
Approx modifier, which is short for Displacement Approximation. This modifier includes three default pre-
sets for Low, Medium, and High that make it easy to use.

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