Pathfinder Operations
Pathfinder is not a cleanup tool. It is a design tool — the primary mechanism for constructing complex diagram shapes from simple component geometry.
Why this matters
Most diagram areas are not simple shapes you can draw from scratch. A "high pedestrian intensity zone" is the overlap of multiple circulation paths plus the entry sequence plus the gathering spaces — a compound shape that would be tedious to draw directly. Pathfinder lets you draw the simple component shapes (all paths, the entry area, the gathering space boundaries) and then combine, subtract, or intersect them to produce the exact compound shape you need. This is how professionals build complex spatial diagrams efficiently.
The Pathfinder panel
Window → Pathfinder. The panel has two rows: Shape Modes (top) and Pathfinders (bottom). Shape modes produce a single unified result from the selected objects. Pathfinders divide or extract without necessarily merging.
Shape modes
| Operation | What it does | Diagram use case |
|---|---|---|
| Unite | Merges all selected paths into one combined outline, removing all internal edges | Combine multiple circulation paths into a single pedestrian zone area; merge overlapping program areas into one composite region |
| Minus Front | Subtracts the frontmost shape from the shape beneath it | Cut a building footprint out of a program area; remove a restricted zone from an otherwise continuous area |
| Intersect | Retains only the area where all selected shapes overlap | Find the exact zone where two diagram conditions co-occur — high pedestrian intensity AND proximity to water; identify spatial conflicts between circulation and planting zones |
| Exclude | Removes overlapping areas and retains only non-overlapping portions | Identify areas that are in one zone but not the other — what is circulated but not programmed; what is accessible but not currently used |
Alt+click any Shape Mode button to apply it as a Live Shape — the component paths remain editable and the result updates if you modify them. Click without Alt to flatten to a single merged path.
Pathfinders
| Operation | What it does | Diagram use case |
|---|---|---|
| Divide | Cuts all selected shapes along every path edge, creating separate closed shapes for every region | Divide a site into distinct analytical zones based on overlapping boundary lines — produces one closed shape per zone, independently colorable and manipulable |
| Trim | Removes hidden (overlapping lower) portions; removes stroke from all results | Clean up stacked diagram areas; remove overlap without merging shapes |
| Merge | Like Trim but also merges adjacent shapes of the same fill color | Useful for consolidating inventory areas before running analysis operations |
| Crop | Crops all selected content to the shape of the frontmost object | Clip diagram content to the site boundary — place the property line shape on top, select all content, Crop |
| Outline | Converts all shapes to their outline strokes, removing fills | Extract edge geometry from filled shapes for use as linework |
Divide for diagram construction
The Divide operation deserves special attention for diagram work. Draw your site boundary and any relevant internal division lines (an edge condition, a circulation axis, a topographic break). Select all of them and run Divide. The result is a set of individually selectable, individually fillable regions — one per enclosed zone. This is the fastest way to build a zonal diagram from linear site information without drawing filled areas from scratch.
Try this
Draw a site boundary rectangle. Draw three overlapping ellipses representing zones of activity intensity — overlapping to show where intensities coincide. Select two ellipses and run Intersect — observe the compound overlap zone. Then try Unite on all three — observe the merged activity zone. Then undo and try Divide on the boundary and all three ellipses — observe the number of individually fillable regions produced. Each operation produces a different piece of analytical information.
What breaks
Running Pathfinder on open paths — most Pathfinder operations require closed paths to produce filled regions. Open paths in the selection produce unpredictable results. Close all paths before running Pathfinder operations, or use Pathfinder only on objects where fill behavior is already confirmed.
Forgetting to expand after Live Shape Mode — an Alt+click Live Shape Mode result looks like a merged shape but is still a compound live object. You cannot apply further Pathfinder operations to it until you expand it (Object → Expand Appearance). Expand when you're confident in the result.