solidcraft-upstream/docs/sketch-patterns.md

Sketch patterns

While editing a sketch, use the PATTERN toolbar group for Mirror, Rectangular Pattern or Circular Pattern. On a narrow window the group collapses to a dropdown. Select several curves before starting a tool, or add them to its Entities input. Each tool previews the result before OK; Escape cancels it.

• Mirror: select the source geometry and a straight sketch Mirror line. Symmetry constraints keep the copies linked to the source and mirror line.
• Rectangular Pattern: pick Direction and optionally Direction 2. Each accepts a straight sketch line or an origin axis in the sketch plane. The lines can meet at any angle. Each direction has its own column with a line picker, quantity, spacing and two icon buttons: Flip direction and Center. Without Center, copies extend from the original along the line from start to end; Flip reverses that direction. Center distributes copies on both sides while the original remains fixed. Quantities are totals including the original: 3 means one copy on either side; 4 means two on one side and one on the other. Flip swaps which side receives the extra copy. Both controls are independent for each direction. Negative spacing reverses the chosen direction. With no direction selected, the first uses sketch X and the second is perpendicular to the first. A second quantity of 1 makes a single row. Picked sketch lines remain live references as they change.
• Circular Pattern: pick a Center point (or click empty sketch space), then set Quantity and Total angle. A full turn distributes instances evenly without duplicating the first; a partial turn includes both endpoints. Center places copies on both angular sides of the original. Flip direction reverses rotation and chooses the extra side for even totals. For six total holes over 90 degrees, the spacing is 18 degrees: the original stays at 0 degrees, with copies at +18, -18, +36, -36 and +54 degrees. Flip moves the last copy to -54 degrees. Five holes over 90 degrees use 22.5-degree spacing and extend 45 degrees either side. Without Center, a positive angle proceeds counterclockwise from the original; Flip reverses it.

Quantities include the original. Edit the original lines or their dimensions to update their copies. Right-click a rectangular or circular pattern instance and choose Edit Sketch Pattern, or double-click its pattern constraint badge, to change the quantities, spacing, directions or angle. Rectangular and circular patterns also appear as children beneath their sketch in the browser and left feature history. Expand the sketch to find them; double-click a pattern to open its saved editor, including from a finished sketch. Surviving copies keep their IDs. Patterns support undo/redo and survive saving and reopening.

The same operations are available through sketch.mirror, sketch.pattern.rectangular and sketch.pattern.circular. For example:

{
  "command": "sketch.pattern.rectangular",
  "params": {
    "entities": ["l1", "l2", "l3"],
    "direction": "guide1",
    "direction2": "guide2",
    "count": 3,
    "spacing": 20,
    "count2": 2,
    "spacing2": 10,
    "alignment": "center",
    "alignment2": "center",
    "reversed": false,
    "reversed2": true
  }
}

direction and direction2 reference sketch line IDs. dir and dir2 instead accept fixed [x,y] vectors. Distances are millimetres; the circular command's angle parameter is in degrees. The combined quantity is capped at 500. Deleting a direction line breaks its rectangular pattern association and leaves the remaining geometry in place; undo restores the association.

Circular patterns accept the same alignment and reversed parameters, for example {"entities":["hole"],"center":[0,0],"count":6,"angle":90,"alignment":"center","reversed":false}.