9

Blend Surface 1185
Start Point 1 and Star t Point 2—
Adjust the position
of the start point at the two edges of the blend.
Adjusting the start points can help eliminate
unwanted twists or "buckles" in the surface.
These spinners are unavailable if the edges or
cur ves are not closed.
While you’re adjusting start points, a dotted
blue line is displayed between them, to show the
alignment. The surface is not displayed, so it
doesn’t slow dow n adjustment. When you release
the mouse button, the surf ace reappears.
Flip Normals—Turn on to reverse the direction of
the blend surface normals.
Blend Surface rollout (modification tim e )
"Tension" affects the tangent between a pa rent
surface and the blend surface. The greater the
tension value, the more closely the tangent
parallels the parent surface, and the smoother
thetransition.Thelowerthetension,thegreater
thetangentangleandthesharperthetransition
between parent and blend.
Tension 1—Controls tension at the edge of the first
surface you clicked. This value has no effect if the
edge is a curve.
Tension 2—Controls tension at the edge of the
second surface you clicked. This val ue has no
effectiftheedgeisacurve.
Flip End 1 a nd Flip End 2—Flip one of the normals
used to construct the blend. A blend surface is
created using the norm als of the parent surfaces.
If the two parents have opposing normals, or
if a cur ve has the opposite direction, the blend
surface can be shaped like a bow tie. To correct
the situation, use Flip End 1 or Flip End 2 to
construct the blend using a normal opposite the
corresponding parent surface ’s normal.
Flip Tangent 1 a nd Flip Tangent 2—Flip the tangent
attheedgeofthefirstorsecondcurveorsurface.
Flipping the tangent reverses the direction in
which the blend surface approaches the paren t
sub-object at that edge.
Flipping the t angent has no effect if the edge is a
curve, unless the curve is a curve on surface.
WhenyoublendtoaCVorpointcurveonsurface,
the new blend surface is tangent to the surface on
which the curve on surface lies. The Flip Tangent
controls are especially useful in this situation.
Start Point 1 and Start Point 2—Adjust the position
of the start point at the two edges of the blend.
Adjusting the start p oints c an help eliminate
unwanted twists or "buckles" in the surface.
These spinners are unavailable if the edges or
curves are not closed.
While you’re adjusting start points, a dotted
blue line is displayed between them, to show the
alignment. The surface is not displayed, so it
doesn’t slow down adjustment. When you release
the mouse button, the surface reappears.
Replace First Edge and R eplace Second Edge—Let
you replace the parent edges or curves. Click a
button, then click the edge to replace the or iginal
firstorsecondedge.Theedgecanbeonthesame