9

Using the Ax is Constraints 437
of a dummy helper object, and then rotating or
scaling the dummy.
Another technique is to offset the pivot point of
your object using the Hierarchy p anel.
For information about linking, dummy objects,
and the Hierarchy panel, see Hierarchies (page
2–416).
Using t he A xi s Cons tra ints
AxisConstraintstoolbar>RestricttoX,Y,Z,oraplane
Keyboard >
F5 restricts to X
F6 restricts to Y
F7 restricts to Z
F8 cycles through the three plane restrictions
The Restr ict to ... buttons, also called the Axis
Constraint buttons, are located on the Axis
Constraints toolbar (page 3–687),whichisoffby
default. You can turn it on by right-clicking an
empty spot on the main toolbar and choosing
Axis Constraints from the pop-up menu. These
buttons let you specify one or two axes about or
along which the transform takes place. They help
you avoid t r ansforming an object in a direction
you didn’t intend.
Note: It’s generally easier to use the Transform
gizmos than these buttons; see Using Transform
Gizmos (page 1–426). However, it is helpful to
understand the concepts explained below.
Axis Constraint buttons
Only one axis constraint can be active at a time.
Whenabuttonisturnedon,transformsare
constrained to the specified axis (or plane). For
example,ifyouturnontheRestrictToXbutton,
you can rotate an object only about the X axis of
the current transform coordinate system.
The axis or axes to which you’re constrained
are highlighted in red on the axis tripod icon in
viewports, or in yellow on the Transform gizmo.
Note: By default, axis constraints don’t apply when
using Snap. You can override this by turning on
Snaps Use Axis Constraint Toggle on the Axis
Constraints toolbar (page 3–687),orbyturningon
Use Axis Constraints in Snap Options (page 2–46).
Note: Constraintsaresetonatransform-by-
transform basis, so select the transform before you
select the axis constraint. If you do not want the
constraints to change, turn on Customize menu >
Preferences > General tab > Reference Coordinate
System group > Constant.
The axis constraints are stored separately at
object and sub-object levels. If you set these
three controls one way while in sub-object mode
and another way while in object selection level,
when you return to sub-object mode, they’re
restored to the way they were previously set. For
example, if you’re using XY constraints at object
level, then switch to sub-object level and use Z
constraint, when you return to object level, XY
will be restored.