9

952 Glossary
Child—
An object controlled by its parent. A child
object can also be a parent to other children. An
objectthatdoesn’thaveanyparentisbydefaulta
child of the world. (The "world" is a n imaginary
object that acts as the root of all other objects in
the scene.)
Ancestors—The parent and all of the parent’s
parents of a child object.
Descendents—The children and all of the children’s
children of a parent object.
Hier archy—The collection of all parents and
children linked together in a single structure.
Root —Thesingleparentobjectthatissuperiorto
all other objects in the hierarchy. All other objects
are descendents of the root object.
Subtr ee—All of the descendents of a selected
parent.
Branch—A path through the hierarch y from a
parent to a sing le descendent.
Lea f —A child object that has no chi ldren of its
own. The lowest object in a branch.
Link —The invisible connection b etween a p arent
and its child. The link is a conduit for transmitting
position, rotation, and scale information from
parent to child.
Pivot—Defines the local center and coordinate
system for each object. You can think of lin ks as
connecting the pivot of a child object to the pivot
of its parent.
Home Gr id
Using the home grid to position houses
Grids are two-dimensional arrays of lines similar
tographpaper,exceptthatyoucanadjustthe
spacing and other features of the g rid to the needs
of your work.
Grids have these primary uses:
• As an aid in visualizing space, scale, and
distance
• As a construction plane where you create and
align objects in your scene
• As a reference system for using snap
The home grid is the basic reference system,
defined by three fixed planes on the world
coordinate axes. The home grid is visible by
defaultwhenyoustartthesoftware,butcan
beturnedoffwithanoptionintheright-click
viewportmenu. Youcanuseanyviewofthe
home grid as a construct ion plane or you can
create a grid object (page 3–951) and use that as a
construction plane instead.