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
- With Egghead selected, select
Edit NURBS > Sculpt Geometry Tool > . In
the Tool Settings window, click Reset
Tool, and make sure the Sculpt parameters are
In the Sculpt Parameters section,
there are a number of 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:
- The Push operation
depresses the surface in the region of the stroke.
- The Pull operation
raises the surface in the region of the stroke.
- The Smooth operation
diminishes bumps or ridges where you drag.
Smoothing works by averaging
the position of all features within the brush radius with all other
- The Relax operation
paints over bumps to relax most of the out of place surface features.
Unlike smoothing, Relax
works by only averaging the largest surface anomalies so that the
overall shape is maintained.
- The Erase operation
eliminates the effects of the other four 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 five operations
on the surface. Don’t be concerned with the results. Just become
familiar with the response to your mouse strokes.
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 the 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
the Pull operation and enter a Radius(U) of
0.25, then drag between a pair of horizontal isoparms without crossing
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
- 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
the changes to the surface as you did previously.
- 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.
TipYou 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.
- Flood-erase the changes to the surface
as you did previously.
- Rotate the camera view so the X axis
of the View Axis points toward you. Draw a vertical Pull stroke
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.
- Erase all changes again, then reposition
the camera view so the Z-axis of the View Axis points
TipIf 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