About merged shapes

The easiest way to create a complex shape is to draw its simple parts and then merge the parts into one complex whole. To merge shapes, select the shapes you want to merge, click the Shape menu, point to Operations, and then click a command.

Operations commands

ShowUnion command

Use the Union command to create a new shape from the perimeter of two or more overlapping shapes. The new shape is a set of all the points that were either in one original or another.

Three triangles side by side showing the result of union command

ShowCombine command

Use the Combine command to create a new shape from selected shapes. If the selected shapes overlap, the area where they overlap is cut out, or discarded. This creates holes in the new shape that make the drawing page grid visible through the shape.

A rectangle cut out from a surrounding rectangle

For example, you can use Combine to create a picture frame shape (a rectangle that has a hole in the middle through which you can see what’s beneath) using the following method. Place a small rectangle in the middle of a larger one. Select the larger rectangle first, then the smaller one, and then on the Shape menu, point to Operations, and click Combine.

ShowFragment command

Use the Fragment command to break a shape into smaller parts or create new shapes from intersecting lines or from shapes that overlap. The Fragment command provides an ideal way to create Venn diagrams (diagrams that use overlapping circles to indicate inclusion, exclusion, and intersection of information) and marketing pyramids. You can use the Fragment command to:

Divide selected shapes into smaller shapes.

A shape divided into two shapes with the Fragment command

Create a new closed shape where two or more closed shapes overlap.

Three circles divided into smaller shapes

Create new shapes from the enclosed spaces of three or more intersecting lines.

A square shape created from four intersecting lines

ShowIntersect command

Use the Intersect command to form a new closed shape from the area where selected shapes overlap, eliminating non-overlapping areas.

Because Visio doesn’t define specific points on a line, nothing is left if you make two overlapping lines intersect.

Rectangle overlapped by triangle showing result of intersect command

ShowSubtract command

Use the Subtract command to create a new shape by subtracting from the primary selection the areas where subsequent selections overlap. For example, if you overlap a polygon and a triangle and select the polygon and then the triangle, using Subtract will remove the overlapping segment of the triangle from the polygon, creating a unique shape.

Heptagon overlapped by triangle showing result of subtract command

ShowJoin command

Use the Join command to assemble individual segments into one or more continuous paths (path: A series of contiguous line or arc segments in a shape. A shape can have more than one path.). The number of paths depends on the configuration of the selected shapes. For example, if the segments lie along a straight line, the new shape will have one path. If the segments are in the form of a 2-D shape (2-D shape: A shape that has four selection handles that you can use to resize the shape proportionally.) such as a rectangle, the new shape will become a closed 2-D shape that you can fill.

Individual line segments formed into a closed shape

ShowTrim command

Use the Trim command to split selected shapes at their intersections. When a shape intersects itself, using Trim creates a new shape for each piece, preserving the styles. If closed shapes are split open, they lose their fill.

The Trim command is similar to the trim operation in Autodesk AutoCAD, although you can trim more than two shapes.

Two lines split at their intersection.

ShowOffset command

Use the Offset command to create a set of parallel lines and curves to the right and left of the original shape. For example, you can create a representation of a two-way road by offsetting a line. You can delete any line or curve you want, even the original, which is always positioned between the offset lines or curves.

Offset shapes inherit line styles from the original shapes. They do not inherit any fill patterns or text from the original shapes.

Two offset diagonal lines positioned on either side of the original line

Offset shapes are positioned on either side of the original shape, at a distance that you specify.

Offset lines extended to create the same angle as the original shape

Offset lines trimmed to prevent them from crossing

When you create an offset shape such as the one to the left of the original angle Callout 1, the duplicated lines are extended to make them meet.
When you create an offset shape such as the one to the right of the original angle Callout 2, a portion of the duplicated lines is deleted to prevent them from crossing.

An offset line and arc that don't intersect

A wide offset that doesn't look like the original shape

In this example Callout 1, extending the arc and the line doesn’t result in an intersection, so Visio creates offset duplicates of each shape and leaves them unconnected.
If the offset is wide, especially inside curves, the offset might not look like the original Callout 2.

ShowFit Curve command

Merging versus grouping shapes

ShowHow Union, Group, and Combine differ

Union, Group, and Combine do not create the same results.

A square inside another square

Original shape: a square inside another square.

Two nested squares after a Merge command

Union merges the perimeter of the two shapes.

Two nested squares after a Group command

Group treats the two shapes as one shape, but you can still manipulate the individual shapes in the group.

Two nested squares after a Combine command

Combine deletes areas where shapes overlap.

Selection order

The result of a merge operation depends partly on the shape you select first (the primary (primary selection: The first selected shape in a multiple selection, indicated on the drawing page by a thick magenta outline. When a multiple selection is combined, the formatting of the primary selection is applied to the new shape.) shape). The primary shape’s formatting is used in the resulting shape, and, in some cases, it even determines the shape of the new shape (when you use the Subtract command, for example).

Merging operations and the ShapeSheet

Merging operations create new shapes. The old shapes, including ShapeSheet (ShapeSheet: The spreadsheet that contains information about a shape; for example, its dimensions, angle, and center of rotation and the styles that determine the shape's appearance.) spreadsheets that define smart behavior, are discarded. The new shape gets its own ShapeSheet spreadsheet.