Select Paths

Select Paths filters which sub-paths from a complex path object are kept. It is especially useful when working with decorative or multi-part fonts where you need the outer letterforms and inner cutout shapes as separate pieces — for example, to 3D print them in two different colors.

How Path Depth Works

When a path object contains shapes with enclosed areas (like the inside of the letter “O”, or the hollow of a decorative swirl), those enclosed areas are holes at depth 1. The outer contour of each letter or shape is at depth 0.

Depth 0 — outer contour of each letter or shape
Depth 1 — first level of enclosed holes (inside an "O", "A", etc.)
Depth 2 — shapes nested inside a hole (rarely used)

Filter Presets

All

Includes every path unchanged. This is the default and equivalent to not applying Select Paths at all.

Outer Paths Only

Keeps only the outer contour of each shape (depth == 0). Use this to get just the letter outlines from a decorative font, without the inner cutout areas.

Holes Only

Keeps only the enclosed holes (depth > 0). Use this to get just the inner cut areas of letters and shapes.

By Group Index

Keeps only paths belonging to one disconnected shape. Group 0 is the first shape, group 1 is the second, and so on. Use this to isolate a single character from a word.

Custom

Write an expression that is evaluated for each path. The path is included when the expression is non-zero and excluded when it is zero.

Expressions must start with = to enable variable substitution. Without =, the value is treated as a plain number (e.g., 1 always includes, 0 always excludes).

Custom Expression Examples

Expression	Effect
=PathDepth==0	Outer contours only (same as Outer Paths Only)
=PathDepth>0	Holes only (same as Holes Only)
=GroupIndex==0	First disconnected shape only
=PathArea>100	Shapes with area larger than 100 mm²
=PathLength>50	Shapes with perimeter longer than 50 mm

Custom Expression Variables

Variable	Meaning
PathDepth	0 = outer contour; 1+ = hole or nested shape
GroupIndex	Index of the disconnected shape (0, 1, 2…)
GroupOuterArea	Area of the outer path for this group
GroupOuterLength	Perimeter of the outer path for this group
ChildCount	Number of holes inside this group’s outer path
PathIndex	Sequential index of this path within its group
PathArea	Area of this individual path
PathLength	Perimeter of this individual path

Example: Multi-Color Christmas Font Print

A common use for Select Paths is printing decorative text where the letters have inner cutout shapes. To print the outer letters in one color and the inner cuts in a second color:

1. Add a Text object and set it to 2D output
2. Apply Select Paths → set preset to Outer Paths Only
3. Apply Linear Extrude to give it height → assign your first filament color
4. Go back to the original text object
5. Apply a second Select Paths → set preset to Holes Only
6. Apply Linear Extrude with the same height → assign your second filament color
7. Position one extruded object on top of the other — the two colors align perfectly

Related

• Linear Extrude — Give the filtered paths height to create a 3D object
• Revolve — Spin filtered paths around an axis
• SVG Object — Import vector paths that may contain multiple sub-paths
• Text — Text objects in 2D mode produce multi-path output