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Surf ace Modifier 843
the splines using an Edit Spline modifier below the
Surface modifier in the modifier stack. Since the
Surface modifier creates a Patch surface, further
refinements can be made to the p atch model by
adding an Edit Patch modifier above the Surface
modifier.
The bulk of the work in using Surface tools to
model lies in creating and editing splines in an
Editable Spline or Edit Spline modifier. One of
the benefits to modeling using splines and Surf ace
Tools is the ease of editing the model. At a lmost
any stage of modeling, you can add a nostril, ear,
limb or body by simply adding splines. This lends
itself to a free-form approach to organic modeling:
you have a mental image of what you want, then
youcreateandeditthesplinenetworkuntilyou
are satisfied.
Note: 3ds Max offers a simplified workflow for this
modeling technique, using Edit/Editable Spline
and the Edit Patch modifier. For details, see To
create a patch object using the Cross Section and
Spline Surface tools: (page 1–639).
Sur fa ce M odifier B asi cs
1. Create a spline object.
2. MakesurethattheSplineverticesformvalid
three-sided or four-sided, closed regions.
Vertices on splines that cross one another
should be coincident.
To make spline vertices coincident, drag
vertices over each other with 3D Snap tur ned
on. 3D Snap must have the Vertex or End Point
option turned on. With 3D Snap turned on,
you can snap to vertices on existing splines
as you create new splines. You can a lso select
vertices and use the Fuse option in an Editable
Spline to make vertices co-incident.
3. Use the CrossSection modifier to connect
spline cross-sect ions, un less you plan on
manually creating the splines that connect the
model’s cross-sect ions.
4. Apply the Surface modifier, then adjust the weld
threshold to generate a patch object. Ideally all
spline vertices that will form a patch surface
are coincident; the Threshold parameter allows
patchcreationevenifverticesarenotquite
coincident.
5. Optionally, add an Edit Patch modifier to edit
the patch surface.
Tip: Make a reference copy of the spline o bject,
then add the Surface modifier to the copy and
edit the original. As you edit the original spline
object, patches appear on the reference copy
as splines form three-or four-sided shapes.
This allows you to view a shaded surface as you
model.
You can take this a step fur ther and add a
Mirror modifier to the reference copy. As you
createsplinesforonesideofaheadorbody,the
reference copy displays an entire model.
Model ing with Surf ace Tools
There are two primary methods of u sing the
Surface modifier to create patch models.
• Create splines that represent a model’s cross
sections, add the CrossSection modifier to
connect the cross sections, and apply the
Surface modifier to create the patch surface.
This approach works for models like the body
of an airplane.
Alternatively, use the editable spline Cross
Section function to connect the cross sections,
and then use the editable patch Spline Surface
tools to create the surface.
• Create a network of splines manually, and then
apply the Surface modifier or editable patch
Spline Surface tools to create the patch surface.
This approach works for modeling a face or
body of a character.