9
1234 Chapter 9: Surface Modeling
Creating a blend and then joining the three
surfaces into a single surface is the better
technique. The result matches the parent surfaces
well. Without the blend step, the resulting surface
can deviate from the parent surfaces, in order to
maintain smo othness. ( The amount of deviation
depends on how far from tangent the two input
surfaces were at the join.)
A problem ar ises when the gap is too small. In this
case, the software generates the blend but because
there isn’t enoug h room for it, the resulting sur face
has a loop. To avoid hav ing this loop, set the
Tolerance higher than the gap distance.
If you set the tolerance to 0.0, the software chooses
a value to use for the Tolerance.
Tension 1—Adjusts the tension of the new surface
at the edge of the first surface you picked.
Tension 2—Adjusts the tension of the new surface
at the end of the second surface you picked.
Prev iew—When on, the effect of the zip or join is
previewed in viewports. Default=on.
Make Loft Dialog
Modify panel > Selec t NURBS surface sub-object. >
Surface Common rollout > Ma k e Loft button
This dialog conv erts a surface sub-object to a
(dependent) U loft or UV loft surface. You can
also change the dimension used to construct a U
loft surface.
Interfa ce
Fr o m U Iso L ines—Usescurvesalongthesurface’sU
dimensiontoconstructaUloft.
Fr o m V Is o Lin e s —Uses curves along the surface’s
V dimension to construct a U loft. If the surface
was already a U loft, set this to change the lofting
dimension.
From U and V Iso Lines—Uses cu rves f rom b oth the
U and V dimensions to construct a UV loft.
UCurves—Sets the number of curves in U.
VCurves—Sets the number of curves in V.
Use Poi nt Curv es—When on, constructs the loft
from point curves instead of the default CV curves.
Default=off.
Ex tr a Point s per S egment—This control is enabled
only for UV lofts (From U and V Iso Lines). Lets
you increase the number of points in each segment.
Fuse Points —This control is enabled only for UV
lofts (From U and V Iso Lines). When on, fuses
points at curve intersections to ensure that the
U and V curves continue to intersect when you
edit the surface, and that the surface remains
coincident with its parent curves. UV lofts