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622 | Chapter 21 Surfacing Wireframe Models
You can see that each end of the area beneath the inlet is described by lines
with curvatures in both directions. This offers you a choice of surfacing
methods, such as a swept surface or a lofted UV surface.
In most cases, there is more than one way to surface an area. Try both methods
here, compare the results, and choose the one that produces the best result.
■ Swept surfaces give you more control over the shape of the mid portion of
the surface.
■ Lofted UV surfaces have fewer controls but risk is minimized.
Once you create a base surface to cover an area, trim the surface back to the
wire with the abrupt edge.
Use trimmed surfaces to create smooth underlying base surfaces that remain
a permanent part of a surface definition. Trim to constrain the edges and you
achieve smoothness in a base surface that contains no abrupt corners in its
boundary wires, yet creates a logical surface bounded by different edges. The
logical surface can contain any number of sharp corners, which have no
effect on the smoothness of the base surface.
The opposite side of the pump top area may also be surfaced several ways.
Again, the surface is really a larger surface cut short by an intersecting area of
the pump. This time, the wire that terminates the surface has no abrupt cor-
ners, so it could be used as one of four sides of a swept or lofted UV surface.
swept surface lofted UV surface
base surface trimmed surface