9

Specifying a Reference Coordinate System 435
Sp ecif y ing a R efer ence Coor dina te
System
The reference coordinate system determines the
orientation of the X, Y, and Z axes used by the
transform. The type of transform system you use
affects all transform operations.
You specify the transform coordinate system using
the Reference Coordinate System list (page 1–443).
Cr e at i n g a Lo ca l Axis
While modeling, it’s often helpful to have a
temporar y, movable local axis s o you can rotate or
scale about an arbitrary center.
Note: This technique does not work for animation.
See Choosing a Transform Center (page 1–435) for
animation tips.
To create an adjustable local axis:
1.
Create a Point helper object.
You can use the Create panel or the Create
menu. On the Create panel, click the Helpers
button, click Point, and then click in a viewport.
Or,chooseCreatemenu>Helpers>Point,and
then click in a viewport.
2. From the Transform Coordinate System list,
choose Pick, and then click the point object.
Thenameofthepointobjectappearsinthelist
astheactivecoordinatesystem.
No w you can use the point object’s coordinate
system as an adjustable axis.
To use the adjustable axis:
1.
Placethepointobjectwhereyouwanttherotate
or scale transform to b e centered.
2. Select the object you want to transform.
3. Choose the point object’s name in the
TransformCoordinateSystemdrop-downlist.
4. From the Use Center flyout (page 1–445) choose
Use Transform Coordinate Center. For more
information, see Choosing a Transform Center
(page 1–435).
5. Proceed with the transform.
Choosing a Tr a nsf orm Center
The transfo rm center affects scale and rotation
transforms, but has no effect on position
transforms.
The software lets you choose from three types of
transform center using the Use Center flyout (page
1–445) on the main toolbar. When you change the
transform center, the junction of the axis tripod
icon moves to the location you specify.
By default, 3ds Max sets the transform center to
Use Pivot P oint center for single objects. When
you select multiple objects, t he default transform
center changes to Use Selection Center, because
selection sets have no pivot point. You can change
the tr ansform center in either case, and the
program remembers and restores the transform
center setting separately for selections of single
and multiple objects (during the current session).
Forexample,youmightselectasingleobjectand
choose Use Transform Coordinate Center, and
then select multiple objects and choose Use Pivot
Point Center. When you next select a single object,
the program switches back to Use Transform
Coordinate Center. Then, when you select multiple
objects, the center switches back to Pivot Point.