Spiral Shapes

Spiral Shapes

Spiral shapes are geometric primitives that generate a spiraling open path from a starting to an ending radius. Spirals can be used as object shapes, or building blocks for more complex shapes.

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

Spirals with different properties: (A) a uniform spiral, (B) a spiral with an initial radius, (C) a spiral with small decay, (D) a spiral with large decay.

Drawing Spirals

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

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

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

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

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

Editing Spirals

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

  • Select the object with a 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 spiral angle and radius position, not at the ending point of the spiral.
  • Adjust the size and radius of the spiral by dragging the outer handle.
  • Adjust the initial radius of the 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.

Spiral Properties

The Spiral view.

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

The following properties can be modified for a spiral shape:

  • Initial - Edit the initial (inner) radius of the spiral.
  • Radius - Edit the (outer) radius of the spiral.
  • Spacing - Edit the amount of spacing between a spiral revolution.
  • Angle - Edit the rotation of the spiral.
  • Decay - Edit the amount of decay in the spiral spacing as it goes from the inside out.
  • Clockwise - Set the spiral shape direction to clockwise or counter-clockwise. The shape direction can be observed with the Node tool tool after converting the spiral to curves.