Part VI: Using Advanced Techniques
When you use surface bodies to trim one another, you must select one of two options: Standard or
Mutual Trim. The Standard option causes one surface to act as the Trim tool and the other surface
to be trimmed by the Trim tool. When you select the Mutual Trim option, both surfaces act as the
Trim tool, and both surfaces are trimmed.For an example of trimmed surfaces, open the mouse example from Chapter 26 and step through
the tree. This shows examples of a couple of types of trimmed surfaces, as well as extended sur-
faces and others.Many people overlook the ability to trim a surface with a plane, which can be very handy some-
times. Planes are infinite, which means you have less to worry about when it comes to changes that
affect features rebuilding correctly.Finally, trimming with 2D sketches is well known, but trimming with 3D sketches is less known.
There is a 3D sketch tool called Spline on Surface that enables you to draw a spline directly on any
surface body. An option exists in the Trim Surface PropertyManager to trim a surface with this type
of sketch. This is very useful in many situations if you can remember that it is available.Fill Surface
The Fill Surface is one of my favorite tools in SolidWorks. I often refer to it as the “magic wand”
because it is sometimes amazing what it can do. It is alternately referred to by the SolidWorks
interface and documentation as either Fill or Filled, depending on where the reference is made.
You will find it listed as both in the SolidWorks interface.
The Fill Surface is intended to fill in gaps in surface bodies. It can do this either smoothly or by
leaving sharp corners. You can use constraint curves to drive the shape of the fill between the exist-
ing boundaries. It can even knit a surface body together into a solid, all-in-one step. Beyond this,
you can use the Fill Surface directly on solid models and integrate it directly into the solid auto-
matically (much like the Replace Face function, which is described later in this chapter).Several rather complex examples of the Fill Surface are found in the bike frame example that was
originally shown in Chapter 12. One of these fills is shown in Figure 27.10.The first thing you should notice about the Fill Surface is that it is creating an oversized, four-sided
patch and trimming it to fit into the available space. This is one of the reasons why I consider this
to be such a magical tool. The four-sided patch I referred to earlier in the section on NURBS is
shown very clearly in this feature preview. Also, the trimmed surface concept is illustrated nicely
by this feature. Not surprising, if you untrim the Fill Surface, then you return to the surface that is
previewed here. In this one function, SolidWorks gives you some useful insight about what is
going on behind the scenes.When using the Fill Surface, it is best to have a patch completely bounded by other surfaces, as
shown in Figure 27.9. Fill Surface can work with a boundary that is not enclosed, but it works
better with a closed boundary.