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426 Chapter 12: Animation
Take, for example, the asymmetrical hierarchy of
dummy helper objects shown below:
At first glance it might appear that Dummies 06,
08 and 02 are siblings of each other, but in pract ice
it is more complicated:
• Selecting Dummy06 and activating Select
Sibling-NextresultsinDummy08being
selected.
• Selecting Dummy06 and activating Select
Sibling - Previous results in Dummy02 being
selected.
• With Dummy02 selected, activating either
SelectSiblingcommandresultsinDummy08
being selected, and the selection cont inues
alternating for each subsequent inv ocation of
either command. This is because 3ds Max looks
only as far as the next branch above the selected
object, resulting in Dummies 02 and 08 being
siblings of Dummy06, but not vice-versa.
Defining a sibling in this way has the practical
advantage of letting you, for example, cycle
through the selection of a ll finger links on one side
of a character without the selection jumping to the
other hand. But cycling through siblings with an
arm object selected usually results in selecting the
opposite arm object.
When using these commands, hidden (page
3–951) and frozen (page 3–945) objects can’t be
selected, but are considered part of the hierarchy
when deciding what is and is not a sibling. Also, if
a selection filte r (page 1–68) is active, siblings that
don’t meet the filter’s criteria cannot be selected.
In all such cases, i neligible siblings are skipped in
favour of a further sibling, if any exists.
Customiz ing the Quad Menu
Yo u c a n c u s t o m i z e t h e quad menu (page 3–694)
so it displays commands to select children, or
ancestors, or both. From the Customize menu,
choose Customize User Interface (page 3–792).On
the Quads (page 3–795) tab, drag Select Ancestor
or Select Children from the list of all commands to
the quad menu. Then you can easi ly select children
or parents with a right-click and then a click.
Animating with For ward
Kinematics
The default method of manipulat ing a hierarchy
uses a technique cal led forward kinematics (page
3–944). The basic principles employed by this
technique are:
•Hierarchicallinkingfromparenttochild
• Placement of pivot points to define the
connecting joint b etween linked objects
• Inheritance of position, rotation, and scale
transforms from parent to child
You animate the objects of a hierarchy in much the
same way you animate anything else. Turn on the
Auto Key button and transform members of the
hierarchy at different frames. However, you need