You can bring other 3ds Max objects
into a NURBS model.
There are two ways to
bring other 3ds Max objects into a NURBS object:
- Attach, which works like Attach for meshes
and splines. It converts the attached object to NURBS format. Once
the object is attached, you can edit it as a NURBS surface or curve.
However, the attached object's history is lost.
For NURBS surfaces,
you can attach other NURBS objects,
The patch is converted to a NURBS surface. Quad patches convert
more successfully than Tri Patches. A converted Tri Patch has a
collapsed internal edge, which gives irregular results when you
manipulate its mesh.
When you convert a spline
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 trim outward instead of inward.
- Import, which works somewhat like the
operand of a
The object is brought into the NURBS object without losing its history.
You can select the imported object as a sub-object.
Here are reasons to use
Import instead of Attach:
- To maintain parametric control over primitives.
For example, if you import
a sphere, you can change its radius directly, which you can't do
after using Attach.
- To use Bezier splines as NURBS curves.
For example, if you want
to use a Bezier spline as a curve in a NURBS model, import it. This
allows you to edit it as a Bezier spline, and not as a NURBS curve.
Surfaces and curves created
by an import are available in the NURBS model. For example, if you
import a box, you can create a blend surface between one of its
polygons and another surface in your NURBS object.
Once you have imported
an object, the NURBS object has an Imports sub-object level. When
you select an import, it is highlighted in red.
It is an error to apply
a modifier to an import when the modifier converts the import into
something that can't be converted to a NURBS object. For example,
if you import a sphere and apply a
it, the sphere converts to an editable mesh, which can't automatically
convert to a NURBS surface. In this case, the import sub-object is
in an error state, and it is displayed in the error color (orange
Imports are displayed
in two different ways. While you work at the NURBS object level
or at a sub-object level other than Imports, imports are displayed
as NURBS curves or surfaces, and use the NURBS object's mesh tessellation
Approximation). However, at the Imports
sub-object level, the selected import is displayed using its native
display format. In other words, it displays as it would if it were
a top-level object. This is because the display must let you edit
the imported object. For example, an imported Bezier spline needs
to display its tangent handles. This wouldn't be possible if it
were displayed as a converted NURBS curve. Leaving the Imports sub-object
level returns to NURBS-style display.
You can extract an imported
object. This creates an independent, top-level object again.
To attach or import an object to a NURBS object:
- Select the NURBS object
and go to the Modify
- (Optional.) Turn on Reorient if you want
to reorient and align the import with the center of the NURBS object.
- Turn on Attach or Import.
At this step, you
can click Attach Multiple or Import Multiple instead. These buttons
From Scene dialog
so you can choose multiple
objects to attach or import.
- Click the object to attach or import.
The mouse cursor changes
shape to indicate a valid object. You can attach curves, NURBS surfaces,
or objects convertible to NURBS.
To extract an imported object:
- Go to the Imports sub-object level and
select the object to extract.
- Click Extract Import on the Import sub-object
If Copy is set (the default),
the extracted object is a top-level copy of the imported object.
If Instance is set, the extracted object is an instance of the imported
object. Initially the extracted object occupies the same space as
the imported object: you must move either the extracted object, the
import sub-object, or the whole NURBS model before you can see the extracted
Attach and Import controls
Lets you attach another object
to the NURBS object. Click to turn on Attach, and then click the
object to attach. If the object you're attaching isn't already a
NURBS object, it is converted to one or more NURBS curves or surfaces
that are sub-objects of the object you're modifying.
- Attach Multiple
Lets you attach multiple objects
to the NURBS surface. Opens a version of the
From Scene dialog, listing the objects
that can be attached. Use the dialog controls to select one or more
objects by name, and then click Attach.
Moves and reorients the object
you are attaching or importing so its creation local coordinate
system is aligned with the creation local coordinate system of the NURBS object.
Lets you import another object
to the NURBS object. Works the same way Attach does, but the imported
object retains its parameters and modifiers.
- Import Multiple
Lets you import multiple objects.
Works the same way Attach Multiple does, but the imported objects
retain their parameters and modifiers.