9

992 Chapter 9: Surface Modelin g
Original mesh display o f model (top) and with increased steps
(bottom)
Show I nterior Edges—Enables the display of the
patch object’s interior edges in wireframe views.
When off, only the objec t’s outline is visible. Turn
on to simplify the display for faster feedback.
Use True Patch Normals—D e ter m ines how the
software smoothes the edges between p atches.
Default=off.
When the check box is off, the software computes
the surface normals from the smoothing groups
of the mesh object to which the p atch object is
converted before rendering. These normals are not
accurate, especially with a low View/Render Steps
setting. When the check box is on, the software
computes true patch normals directly from the
patchsurfaces,whichcangeneratemoreaccurate
shading.
In the illustrat ion below, a sphere was converted
to Editable Patch format, and then a vertex was
moved toward the center and rotated. The sphere
onthelefthasUseTruePatchNormalsturnedoff,
and the one on t he right h as it turned on. In b oth
cases, View Steps was set to 8.
A p atch sphere with Use True Patch Normals off (left) and on
(right).
Miscellaneous group
Cr e a te Shape ( Edg e l e vel o n ly ) —Create s splines
based on the selected edges. If no edges are
selected, then splines are created for all the patch
edges.3dsMaxpromptsyouforaname:typeina
name for the new shape object, and then click OK.
Each patch edge forms an individual spline. You
can use this to create a spline cage based on
patchedges.Thisisusefulforsplinemodelingor
working with surface tools.
Patch Smooth—At the sub-object level, adjusts
the tangent handles of the ver tices of selected
sub-objects to smooth the surface of the patch
object. At the object le vel, adjusts all tangent
handles to smooth the surface.
PatchSmoothsetsthehandlestoabsolute
positions based on the patch object geometry;
repeated applications have no effect.