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Viewing and Changin g Smo othing 167
•ApplyaNormal modifier (page 1–746).IfaFace
sub-object selection is active, Normal applies
to the selected faces. If no faces are selected,
Normal applies to the entire object.
•ApplyanEdit Mesh modifier (page 1–634),
enable Face, Pol ygon or Element sub-object
mode, and then use the features on the Surface
Properties rollout to change the d irections in
which normals point.
•Converttheobjecttoaneditable mesh (page
1–996), enable Face, Polygon or Element
sub-object mode, and use the features on the
Surface Properties rollout
Viewing Normals
The easiest way to view normals is to look at an
object in a shaded viewport. In this case, you are
not viewing the normal arrows themselves, but
rather their effects on the shaded surface. If the
object looks as if it is inside-out, or has holes, then
some of the normals might be pointing in the
wrong direction.
You can display the normal vectors for selected
faces or vertices by enabling Show Normals on the
Selection rollout of an editable mesh object or the
Edit Mesh modifier.
Unify ing Nor mals
Use Unify Normals to make normals point in a
consistent direction. If an object has normals that
are inconsistent (s ome point outward and others
inward) the object will appear to have holes in its
surface.
Unify Normals is found on the Surface Properties
rollout and on the Normal modifier.
If you are animating the creation of a complex
object such as a nested B oolean or a loft, and you
think the operation mig ht result in inconsistent
faces, apply a Normal modifier (page 1–746) to the
result, and turn on Unify Normals.
Flipping Nor ma ls
Use Flip Normals to reverse the direction of all
selected faces. Flipping the norma ls of an object
turns it inside-out.
Flip Normals is found on the Surface Properties
rollout and on the Normal modifier.
The Lathe modifier (page 1–707) sometimes creates
an object with normals pointing inward. Use the
Flip Normals check box on the Lathe modifier’s
Parametersrollouttoadjustthenormals.Youcan
also use t he Normal modifier with both Unify and
Flip turn ed on to fix inside-out lathed objects.
Viewing and Changing Smoothi ng
Smoothingblendstheshadingattheedges
between faces to produce the appearance of a
smooth, curved sur face. You can control how
smoothing is applied to a surface so your objects
canhavebothsmoothsurfacesandsharpfaceted
edges at the appropriate places.
The face labeled “1-2” shares smoothing groups with adjacent
faces, so the edges between them are smoothed over in
renderings.
The face labeled “3” does not share a smoothing group, so its
edge is visible in renderings.
Smoothing does not affect geometr y. It affects only
the way geometry is colored when rendered.