Guide · Boolean
Combine regions from curve intersections.
The five Boolean commands work on the curve model, so what comes out is still an editable path.
Five commands, five questions.
Unite keeps everything covered by any selected drawing. Subtract removes the later drawings from the first. Intersect keeps only the region covered by all of them. Exclude keeps the region covered by an odd number of them. Divide splits the selection into the separate faces its outlines produce.
Each command is computed from curve-to-curve intersections rather than from a rasterized or polygonized approximation, so lines, quadratic and cubic Béziers, and elliptical arcs survive the operation as curves.
- Unite, subtract, intersect, exclude, divide
- Computed from exact curve intersections
- Result remains an editable path
A future comparison will show the same two shapes under each of the five commands.
A command that cannot apply stays unavailable.
Boolean commands enable only for a selection they can actually process. An unavailable command is information: it says the current selection is not the input the operation needs.
When an operation runs but leaves nothing behind, the empty result is reported rather than silently applied. Subtracting a shape that fully covers its target is a legitimate outcome you should be told about.
Compound paths hold several subpaths as one drawing.
The compound path command joins the selected drawings into a single path with multiple subpaths, which is how a filled shape carries its holes. Break apart performs the reverse and returns the subpaths as independent drawings.
A compound path shares one paint and one transform across all of its subpaths. That is the point of it: the hole and the body cannot drift apart or be styled inconsistently.
- Compound path merges drawings into one path
- Break apart returns independent drawings
- One paint and one transform for the whole compound
Direction decides which enclosed regions read as inside.
The direction menu reports and sets the orientation of a path: start to end or end to start for an open path, clockwise or counter-clockwise for a closed one. Under the nonzero fill rule this direction decides whether an inner subpath is a hole or a solid island.
If a hole fills in after a Boolean operation, check the direction of the inner subpath and the fill rule together before moving any node. The geometry is usually correct and only the winding needs reversing.
- Open path: start to end, or end to start
- Closed path: clockwise or counter-clockwise
- Nonzero fill depends on direction; evenodd does not