Page 305 - Kitab3DsMax

Chapter 9: Grouping, Linking, and Parenting Objects

Selecting hierarchies
You need to select a hierarchy before you can transform it, and you have several ways to do so. The easiest
method is to simply double-click an object. Double-clicking the root object selects the entire hierarchy, and
double-clicking an object within the hierarchy selects it and all of its children.
After you select an object in a hierarchy, pressing the Page Up or Page Down keyboard shortcut selects its
parent or child objects. For example, if you select the Mommy duck object and press Page Down, the first
baby duck object is selected and the Mommy duck object is deselected. Selecting any of the baby duck
objects and pressing Page Up selects the duck object in front of it.

Linking to dummies
Dummy objects are useful as root objects for controlling the motion of hierarchies. By linking the parent
object of a hierarchy to a dummy object, you can control all the objects by moving the dummy.
To create a dummy object, select Create ➪ Helpers ➪ Dummy, or open the Create panel, click the Helpers
category button (this button looks like a small tape measure), and select the Standard category. Within the
Object Type rollout is the Dummy button; click it, and then click in the viewport where you want the
dummy object to be positioned. Dummy objects look like wireframe box objects in the viewports, but
dummy objects are not rendered.
Tutorial: Circling the globe

When you work with complex models with lots of parts, you can control the object more easily if you link
it to a Dummy object and then animate the dummy object instead of the entire model. To practice doing
this, you’ll create a simple animation of an airplane flying around the globe. To perform this feat, you create
a dummy object in the center of a sphere, link the airplane model to it, and rotate the dummy object. This
tutorial involves transforming and animating objects, which are covered in other chapters.
Cross-Ref
Rotating objects is covered in Chapter 7, “Transforming Objects, Pivoting, Aligning, and Snapping,” and the basics
of animation are covered in Chapter 21,“Understanding Animation and Keyframes.” n
To link and rotate objects using a dummy object, follow these steps:
1. Open the Circling the globe.max file found in the Chap 09 directory on the DVD.
This file includes a texture mapped sphere with an airplane model positioned above it. The air-
plane model was created by Viewpoint Datalabs.
2. Select Create ➪ Helpers ➪ Dummy, and then drag in the center of the Sphere to create a Dummy object.
With the Dummy object selected, choose the Tools ➪ Align menu command (or press the Alt+A shortcut)
and click on the globe. In the Align Selection dialog box, enable the X, Y, and Z Position options along
with the Center options and click OK to align the centers of the dummy and globe objects.
3. Because the dummy object is inside the sphere, creating the link between the airplane and the
dummy object can be difficult. To simplify this process, select and right-click the sphere object,
and then select Hide Selection from the pop-up menu.
This hides the sphere so that you can create a link between the airplane and the dummy object.
4. Click the Select and Link button on the main toolbar, and drag a line from the airplane to the
dummy object.
5. Click the Auto Key button (or press N) to enable animation key mode, and drag the Time Slider
to frame 100. Then click the Select and Rotate button on the main toolbar (or press E), and select
the dummy object. Then rotate the dummy object about its X-axis, and notice how the linked
airplane also rotates over the surface of the sphere.
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