Using a Mask to Split Vector Objects

The mask concept allows for the adjustment of one object using another that serves to trim or intersect it. The mask defines which portions of the original object remain and which are removed. This effect is achieved through the Shaping operations: Intersection and Difference.

Fig. 1. Ring with multi-color segments.

Consider a design requirement for a ring with multi-color segments, as shown in Figure 1. Rather than digitizing each segment individually, the entire ring is created first and subsequently split using a secondary object.

Fig. 2. Initial complete ring object.

The process begins by creating a large ring. In this example, a fill object with a central opening (hole) is used.

Fig. 3. Placement of the mask object.

Next, draw the object that will serve as the splitting mask. The ring will be sliced at the paths where the mask crosses the ring (indicated by the thick lines). Consequently, the mask edges must be drawn precisely at the paths of intersection with the ring; other areas may be drawn with less precision.

In this example, a fill object is used as the mask. While a mask can be almost any fill object type (such as Sfumato, Mesh or Column), linear objects like outlines, connections, or manual stitches cannot be used. This is because shaping operations require a closed area to calculate the Difference or Intersection.

Because the mask is a temporary tool and will not contain stitches, its start/end points and specific parameters are irrelevant. A mask may also contain one or more openings, which allows you to split multiple sections of the underlying object simultaneously..

Fig. 4. Selection of the ring and mask.

Select both the ring and the mask object, then navigate to Main Menu > Build > Shaping > Difference. This command generates new objects representing the ring area minus the mask area, as shown in Figure 5. The original ring object and the mask object remain untouched.

Fig. 5. Resulting objects after the Difference operation.

This step is critical: without sufficient overlap, the "pull effect" of the embroidery thread will cause visible gaps in the final sew-out.

Select the mask object and navigate to Main Menu > Transform > Offset > Expand Objects.

Fig. 6. Expanding the mask for overlap compensation.

Now, select the original ring and the expanded mask. Navigate to Main Menu > Build > Shaping > Intersection to create areas common to both objects.

Fig. 7. Resulting Intersection objects.

This results in objects that are complementary to the initial yellow segments. Change their color to red by dragging the desired shade from the palette onto the selected objects. Finally, delete the original ring and mask objects; they have served their purpose as temporary templates and are no longer required.