Share points between shapes

A shared point is a single vertex referenced by several shapes. Move it once and every shape that references it follows. Use this to keep adjoining lane boundaries, polygon corners, and path joints locked together.

Hold Alt + click to share an existing point with a new shape.

Create a shared point while drawing

1. Pick the Linestring (L), Polygon (G), or Path (H) tool.
2. Hold Alt (Option on macOS).
3. Click an existing vertex of another shape.

The new shape gains a vertex that’s shared with the existing one — not just snapped to the same coordinate.

Convert an existing vertex to a shared one

1. Double-click a shape to enter segment editing.
2. Hold Alt and drag a vertex onto an existing one.

Visual cue

Shared points render as a doubled handle in segment-editing mode. Plain snapped points render as a single handle.

See also

• Snap & point sharing model — why shared and snapped are different things.