Polygonal Spiral Shapes

Polygonal Spiral Shapes

Polygonal spiral shapes are geometric primitives that generate a spiraling open path from a starting to an ending radius, using straight lines instead of curves. Polygonal spirals can be used as object shapes, or building blocks for more complex shapes.

The properties of a polygonal spiral shape can be edited using the Node tool tool or the Shape panel.

Polygonal spirals with different properties: (A) a polygonal spiral with 3 sides, (B) a polygonal spiral with 5 sides, (C) a polygonal spiral with 7 sides, (D) a polygonal spiral with 5 sides and bending of the sides.

Drawing Polygonal Spirals

Polygonal spirals can be drawn using the Polygonal Spiral tool from the application toolbox. To draw a polygonal spiral:

  • Select the Polygonal Spiral tool from the toolbox.
  • Press the mouse on a starting location on the canvas, this will be the center of the polygonal spiral.
  • Drag the mouse to set the polygonal spiral radius and rotation.
  • Hold the Control key to restrict the polygonal spiral rotation to user specified increments (5 degrees by default).
  • Release the mouse to create a polygonal spiral with the selected radius and rotation.

When the document view is rotated, the polygonal spiral shape will be drawn with the opposite rotation angle to the view.

The default polygonal spiral options can be set by double clicking on the Polygonal Spiral tool icon in the toolbox. For example: the spacing of the polygonal spiral can be set before drawing the polygonal spiral.

To create a polygonal spiral by setting the numeric properties of the shape, click at a point on the canvas. This will open the Polygonal Spiral view (described below) that contains all the polygonal spiral shape properties. Set the required values and press Ok to create a new object with a polygonal spiral shape.

Editing Polygonal Spirals

The Node tool tool can be used to interactively edit polygonal spiral shapes:

  • Select the object with a polygonal spiral shape.
  • Select the Node tool tool from the application toolbox.
  • An inner and outer handle is shown. The outer handle is shown at the polygonal spiral angle and radius position, not at the ending point of the spiral.
  • Adjust the size and radius of the polygonal spiral by dragging the outer handle.
  • Adjust the initial radius of the polygonal spiral by dragging the inner handle.
  • Hold the Control key to restrict the rotation to user specified increments.
  • Hold the Shift key to change only the radius and keep the angle fixed.
  • Hold the Option key to change only the angle and keep the radius fixed.

Polygonal Spiral Properties

The Polygonal Spiral view.

The properties of a polygonal spiral shape can be edited in the Shape panel when the shape is selected, or in the Polygonal Spiral view, either from the shape panel, or when editing a shape style.

The following properties can be modified for a polygonal spiral shape:

  • Initial - Edit the initial (inner) radius of the polygonal spiral.
  • Final - Edit the final (outer) radius of the polygonal spiral.
  • Spacing - Edit the amount of spacing between a polygonal spiral revolution.
  • Angle - Edit the rotation of the polygonal spiral.
  • Decay - Edit the amount of decay in the polygonal spiral spacing as goes from the inside out.
  • Bending - Edit the amount of bending of the sides of the polygonal spiral.
  • Sides - Edit the number of sides used in one revolution of the polygonal spiral.
  • Clockwise - Set the polygonal spiral shape direction to clockwise or counter-clockwise. The shape direction can be observed with the Node tool tool after converting the polygonal spiral to curves.
  • Quadratic Bend - Select the use of quadratic curve segments when the sides of the polygonal spiral are bent. If unchecked, the bent sides will use cubic curve segments.