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   Elliptical Arc (node)

An arc running along an ellipse.

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The center, major-axis point, and minor-axis point define an underlying ellipse exactly as in Ellipse; the Start and End points then mark where the arc begins and ends along that ellipse. The result is an open curve, not a closed region. It pairs all five point lists index-for-index, one arc per set.

Inputs

• Center (point): the center of the underlying ellipse.
• Major Axis (point): a point on the long axis (major radius + tilt).
• Minor Axis (point): a point on the short axis (minor radius).
• Start (point): where the arc begins along the ellipse.
• End (point): where the arc ends.
• Long Way (on/off): sweeps the reflex side, over 180 degrees, instead of the short way.

Outputs

• Arc (curve): one open elliptical arc per set of points.

What it is for

A slice of an ellipse, for the curves a circular arc cannot make: anything that has to be wider one way than the other, or to lean.

Five points is a lot to wire, so the practical route is usually to get the ellipse looking right first, then decide where the arc should start and stop. Start and End say where along the ellipse, and Long Way picks which of the two ways round it takes.

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Related

• In the modeling view: Elliptical Arc - draw the same elliptical arc directly on the canvas.