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How to Fix NURBS Objects 1099
If a curve is dependent or a point curve, first
youwillhavetomakeitindependent(thisalso
improves performance).
Curves that are made of two joined curves
have this problem more often than others.
Ifyouhaveajoinedcurveasoneofthe
curves to construc t the loft, reparameterize it
before you create the loft, or set the curves to
reparameterize automatically.
•TheEditCurvebuttonletsyoudirectly
transform the CVs of a curve within a U loft
or
UV loft (page 1–1202) , without changing
the sub-object level. Edit Cur ve also g ives you
access to all the rollouts that control t he curve.
YoucanuseRefineorMakeFirst,forexample,
without changing levels.
• To close a UV loft, you c an pick the first V
curveagaintomakeitthelastcurveintheloft.
Sometimes a seam is visible at this location in
the UV loft.
Multisided B lend Sur fa ces
•Iftheprogramdoesn’tcreatethe multisided
blend (page 1–1215)
,fusetheCVsatthethree
or four corners. Snapping CVs to each other
doesn’t a lways succeed, b ecause of rounding
off.
Multicur ve Tr immed Sur fa ces
• Multicurvetrimmedsurfacesaretheonlyway
to create a trimmed hole that contains sharp
angles.
Displ acement M apping
• In general, the default tessellation sett ings
aren’t suitable for displaced surfaces. With
these default settings, displacement mapping
can create an
extremely high face count,
which performs very slowly. Change the
surfaceapproximationtothelowestnecessary
resolution. A good rule of thumb is to start
with Spatial approx imation and an E dge value
of 20. If that is too low, reduce the Edge value
untilthemodellooksasitshould.
•Usethe
Displace NURBS world space modifier
(page 1–501)
to convert the displacement map
into an ac tual displaced mesh so you can see the
effect of displacement in viewport s. To make a
displaced mesh copy of the NURBS model, use
Snapshot (page 1–438) .
Connecting a n A r m to a S houlder
• The easiest approach is to create a CV curve
on surface (page 1–1174)
or normal projected
cur ve (page 1–1171)
on the shoulder. Then
create the arm as a
U loft (page 1–1197) .For
the last curve of the U loft, select the CV curve
on surface or the normal projected curve. Then
turn on Use COS Tangents, which makes t he
loftsurfacetangenttotheothersurfacewhere
the arm joins the shoulder.
• If the blend appears twisted, use the Start Point
spinner to change the location of the first point
ofthecurvesthatmakeuptheUloftsurface.
• Another way to connect a U loft to another
surfaceistoprojectthelastcurveintheU
loft onto the other sur face. Click Make COS
to convert the projected curve into a curve on
surface,andthenontheULoftSurfacerollout
click Insert to make the new curve on surface
the last curve in the U loft. You c an scale the
curve on surface or move its CVs to get the
curvature and blending you want.
How to Fix NURB S Objects
These are tips on fixing problems with NURBS
models.
• Ifyoucreateasurfacebutitisn’tvisiblein
viewports,clickFlipNormals.FlipNormalsis
available on the surface’s creation rollout, or