Part VI: Using Advanced Techniques
introduce surfacing functions to those of you who do not typically use surfaces. I am not showing
how surfaces are used in the context of creating complex shapes, just how you can use them for
various general 3D modeling tasks.The word surfacing has often been used (and confused) to signify complex shapes. Not all surface
work is done to create complex shapes, and many complex shapes can be made directly from solids.
Many users think that because they do not make complex shapes, they never need to use surface fea-
tures. This chapter shows mainly examples that do not require complex shapes, in situations where
surfaces make it easier, more efficient, or simply possible to do the necessary tasks.While some of the uses of surfaces may not be immediately obvious, by the end of this chapter,
you should have enough information and applications that you can start experimenting to increase
your confidence in surfacing techniques.Understanding Surfacing Terminology
When dealing with surfaces, you may hear different terminology than the terminology typically
used with solid modeling. This special terminology also often exists for surfaces because of impor-
tant conceptual differences between how solids and surfaces are handled.These terms are fairly universal among all surfacing software. The underlying surface and solid
construction concepts are generally uniform between the major solid and surface modeling pack-
ages. What varies from software to software is how the user interacts with the geometry through
the software interface. You may never see some of these terms in the SolidWorks menus, Help files,
training books, or elsewhere, but it becomes obvious as you use the software that the concepts are
relevant.Knit
Knit is analogous to the solid feature Combine in that it joins multiple surface bodies into a single
surface body. Unlike Combine, Knit does not perform the subtract or intersect Boolean operations.
It also has an option to create a solid if the resulting surface body meets the requirements (a fully
enclosed volume without gaps or overlaps). However, unlike the solid bodies in Combine, which
may overlap volumetrically, surface bodies must only intersect edge to edge, more like sketch enti-
ties that can only touch end to end.
Knit is also sometimes used in the same way that the zero-distance offset is used, to copy a set of
solid faces to become a new surface body.You can find one nice option that enables you to quickly see where the boundaries of a surface
body lie by choosing Tools ➪ Options ➪ Display/Selection ➪ Show Open Edges Of Surfaces
In Different Color. By default, this color is a medium blue, and you can change it by choosing
Tools ➪ Options ➪ Colors ➪ Surfaces ➪ Open Edges.