Set the RebarShapeDefinitionByArc.Type property to Spiral.

Namespace: Autodesk.Revit.DB.Structure
Assembly: RevitAPI (in RevitAPI.dll) Version: 24.0.0.0 (24.0.0.0)
Since: 2011

Syntax

C#
`public void SetArcTypeSpiral( double height, double pitch, int baseFinishingTurns, int topFinishingTurns )`

Visual Basic
`Public Sub SetArcTypeSpiral ( _ height As Double, _ pitch As Double, _ baseFinishingTurns As Integer, _ topFinishingTurns As Integer _ )`

Visual C++
`public: void SetArcTypeSpiral( double height, double pitch, int baseFinishingTurns, int topFinishingTurns )`

height: Type: SystemDouble
The height of the spiral (assuming the spiral is vertical).

pitch: Type: SystemDouble
The pitch, or vertical distance traveled in one rotation.

baseFinishingTurns: Type: SystemInt32
The number of finishing turns at the lower end of the spiral.

topFinishingTurns: Type: SystemInt32
The number of finishing turns at the upper end of the spiral.

Remarks

In order to create a spiral definition, you must provide default values for height, pitch, and finishing turns.

Exception	Condition
Autodesk.Revit.ExceptionsArgumentException	baseFinishingTurns is not between 0 and 100. -or- topFinishingTurns is not between 0 and 100.
Autodesk.Revit.ExceptionsArgumentOutOfRangeException	The given value for height must be greater than 0 and no more than 30000 feet. -or- The given value for pitch must be greater than 0 and no more than 30000 feet.