To practice sculpting using basic sculpting operations Basic sculpting techniques

Preparing a surface for sculpting

Because a head is roughly spherical, you can create a primitive sphere as a quick starting point for
creating a head and face.

To prepare a sphere for sculpting
1. Make sure you've done the steps in NURBS Lessons: Preparing for the lessons.
2. Select Create > NURBS Primitives > Sphere > . In the options window, select Edit > Reset
Settings, enter the following values, then click the Create button:
o Radius: 6
o Number of Sections: 30
o Number of Spans: 30

The Radius sets the sphere's size in grid units. A value of 6 creates a sphere big enough to use
the grid for size comparison.
The Number of Sections sets the number of vertical curves, called isoparms, for the sphere.
Isoparms show the outline of the surface shape. The more isoparms a surface has, the more CVs it
has. (By default, CVs are not displayed.) More CVs means better precision as you edit a surface.
The Number of Spans sets the number of horizontal isoparms.
The drawback to having too many CVs is that you'll have a harder time making smooth shape
changes to broad regions. Lots of CVs also means slower processing time as you work with the
surface. It's best to make surfaces with as few CVs as necessary.
We chose 30 Sections and Spans for this lesson because experience has shown that this allows
adequate facial subtlety without slowing Maya operation on a workstation of modest processing
power.

Note
In wireframe display mode, if you select Display > NURBS Smoothness > Fine or Medium, more isoparms
appear than there are actual spans and sections. The surface is visually displayed with extra precision,
but the extra isoparms have no CVs and cannot be edited.
3. Name the sphere Egghead.
4. Rotate the sphere 90 degrees on its side (Rotate Z: 90). This positions the sphere's CVs well for
modeling a simple head and face. You'll learn why later in this lesson.

 

5. To give Egghead an oval shape, set the ScaleX for the sphere to 1.3 or so. Optionally, you can
move Egghead above the grid so the grid doesn't interfere with your view of Egghead. Also,
position the camera view so the Z-axis of the View Axis points toward you.

Modifying the surface material for easier viewing
Because you will do subtle surface modeling in this lesson, it's helpful to display Egghead with bright
highlights so you can clearly see the effects of the changes you make. In the next steps, you'll assign a
Blinn material to Egghead to give its surface bright highlights. The steps have no explanations, as the
shading subject matter is the focus of a later lesson.

To assign a Blinn surface material
1. With Egghead selected, press 5 to display the surface with smooth shading.
2. Right-click Egghead and select Materials > Assign New Material > Blinn.
The Attribute Editor will immediately be displayed for the Blinn material.
3. Drag the Color attribute slider roughly 3/4 of the way to the right, set Eccentricity to 0, and
close the window.

 

Basic sculpting techniques
In the next steps, you'll become familiar with features of the Sculpt Geometry Tool. With this tool, you
use your mouse or stylus to push, pull, or smooth a surface's shape without selecting or displaying CVs.
After you practice sculpting the surface, you'll erase your practice strokes then begin sculpting Egghead's
features.

To practice sculpting using basic sculpting operations
1. With Egghead selected, select Edit NURBS > Sculpt Geometry Tool > . In the Tool Settings
window, click Reset Tool, and make sure the Sculpt parameters are displayed.
In the Sculpt Parameters section, there are four operations for sculpting a surface. Each affects
the region of the surface where you drag (stroke) your mouse or stylus relative to the surface
normals:

o The Push operation depresses the surface in the region of the stroke.
o The Pull operation raises the surface in the region of the stroke.
o The Smooth operation diminishes bumps or ridges where you drag.
o The Erase operation eliminates the effects of the other three operations. The Erase operation
works up to the last time you saved the scene or clicked the Update button to the right of
Erase Surface.

 Experiment with each of the four operations on the surface. Don't be concerned with the results.
Just become familiar with the response to your mouse strokes.

By default, Push and Pull strokes deform the surface in a direction normal (perpendicular) to the
surface. To create the resulting deformation more accurately, use Push and Pull strokes in a front,
side, or top view while examining the results in a separate perspective view. Tumble the
perspective view regularly for best visual feedback.
When you position the mouse pointer on the surface, it changes to a red sculpt icon that shows
an abbreviation for the name of the operation you are performing. For instance, Ps stands for
Push.
The red icon also displays the radius of the region affected by the stroke. The Radius(U) value
changes the radius.
 Select the Erase operation and click the Flood button. This erases all your changes.

4. Select the Pull operation and enter a Radius(U) of 0.25, then drag between a pair of horizontal
isoparms without crossing either.
This has no effect because the stroke radius didn't make contact with the CVs of either isoparm.
Regardless of which operation you use, only CVs are affected by the strokes.
5. Change the Radius(U) to 2 and repeat the prior strokes.

 

The strokes alter the surface because the radius overlaps the CVs. As this example shows, you
need to make sure the radius is big enough to influence the desired CVs. It's common to change
the radius many times during a sculpting session.
If you prefer to affect a small region without increasing the radius, you can add CVs to the region
by inserting more isoparms. You'll do this later in the lesson.
6. Flood-erase the changes to the surface as you did previously.
7. Select the Pull operation with a Radius(U) of 0.5. Drag along a vertical isoparm. For comparison,
drag along a horizontal isoparm.

 

The vertical stroke creates a thinner ridge than the horizontal stroke because the density of
vertical isoparms is greater. The number of underlying CVs and their positioning affects the
outcome of your strokes.
Tip
You can alternatively adjust the radius of the Sculpt Geometry Tool using a Hotkey. Move the tool
over the object, press and hold the b Hotkey and drag left or right. The circle on the object with
numerical radius value represents the size of your tool. Stroke on the object to try out a new size
8. Flood-erase the changes to the surface as you did previously.
9. Rotate the camera view so the X axis of the View Axis points toward you. Draw a vertical Pull
stroke again.

As your stroke nears the center of Egghead, a kink occurs. It's challenging to alter a surface
symmetrically in a region where many isoparms converge at a single point, called a pole. Always
consider the position of isoparms as you sculpt a surface. In general, sculpt where isoparms are
evenly, regularly distributed.
10.Erase all changes again, then reposition the camera view so the Z-axis of the View Axis points

     toward you.
Tip
If the Sculpt Geometry Tool is selected but not the surface you want to work on, right-click the
surface and select Select from the marking menu.