8

Attaching and Importing 3ds Max Objects 1121
ULinesandVLines—
The number of lines used to
approximate the NURBS surface in viewports,
alongthesurface’slocalUandVdimensions,
respectively. Reducing these values can speed up
the display of the surface, but reduce accuracy
of the display. Increasing these values increases
accuracy at the expense of time. Setting one of
these values to 0 displays only the edge of the
object in the corresponding dimension.
Iso and mesh displays of a NURBS teapot
Iso Only—When chosen, all viewports display iso
line (page 3–1053)
representations of the surface.
Iso(parametric) lines are similar to contour lines.
ThelinesshowwheretheNURBSsurfacehas
a constant U value or V value or both. Iso line
representations can be less crowded and easier to
visualize t han wire mesh repre sentations.
Iso a nd Mesh—(The default.) When chosen,
w i reframe viewports display iso line
representations of the surface, and shaded
viewports display the shaded surface.
Mesh Only—When chosen, wireframe viewports
display the surface as a wire mesh, and shaded
viewports display the shaded surface. In wireframe
viewports, this option lets you see the
surface
approximation (page 1–1241)
used for v iew por ts.
Cr eating and Editing NUR BS
Sub-Objects
Attaching a nd I mpor ting 3 ds Ma x
Objects
Modify panel > S elect NURBS object. > G eneral rollout >
Attach button, Import button, and related controls
There are two ways to bring other 3ds Max objects
into a NURBS object:
• Att ach, which works like Att ach for meshes
and splines. It converts the attached object to
NURBS format. Once the object is attached,
you can edit it as a N URBS surface or curve.
However, the attached o bject’s history is lost.
Note: For NURBS surfaces, you can attach
other NURBS objects,
standard primitive (page
1–165)
objects, or quad patch (page 1–981) and
tri patch (page 1–983) surfaces. The patch is
converted to a NURBS surface. Quad patches
conv ert more successfully than Tri Patches. A
converted Tri Patch has a collapsed internal
edge, w hich gives irregular results when you
manipulate its mesh.
When you convert a spline
circle (page 1–268)
to a NURBS curve, the direction of the curve
is reversed. This facilitates using the curve to
trim a surface: if the direction weren’t reversed,
usually the circle would t rim outward instead
of inward.
• Import, which works somewhat like the
operand of a
Bo olean (page 1–333) .Theobject
is brought into the NURBS object without
losing its history. You can select the imported
object as a sub-object.
Using Imports
HerearereasonstouseImportinsteadofAttach: