Drawing a Three-Point Arc Line

In the modeler, a three-point arc line segment is an arced line defined by three points on its curve. Use the Draw > Arc > 3 Point function to create a polyline object with one or more arc line segments.

  1. Click Draw > Arc > 3 Point.
  2. Select the start point of the arc in one of the following ways:
    • Click the point.
    • Type the point’s coordinates in the X, Y, and Z text boxes in the status bar.
  3. Select the midpoint of the arc by clicking the point or typing the coordinates in the X, Y, and Z text boxes in the status bar.
  4. To delete the last point that was entered, click Undo Previous Segment on the shortcut menu. After using the undo feature, you can also use Redo Previous Segment on the shortcut menu.

    To delete all points and start over, press Esc or click Escape Draw Mode on the shortcut menu.

  5. Select the endpoint of the arc by clicking the point or typing the coordinates in the X, Y, and Ztext boxes in the status bar.
  6. The endpoint serves as the start point for a subsequent arc line segment.

  7. If the endpoint is the last point of the polyline object, double-click the point to complete the polyline or click Done on the shortcut menu.
  8. If the Modeler option for editing properties of new primitives is checked, the Properties window appears, in which you can modify the object’s attributes. Those listed under the Command tab describe the commands used to create the object. These commands also appear in the History tree. The properties listed as line attributes include Name, Orientation, whether a Model object, whether to Display Wireframe, Color, Transparency, and whether to Show Direction as arrows. The Show Direction property is most helpful to unambiguously show the line start orientation when plotting fields along a line.

  9. Click OK.

Based on the three points you specified, the modeler calculates the center point and radius of the arc and draws an arced line through the three points.

Note: While drawing a polyline, you can switch between arc line, straight line, or spline segments using the Set Edge Type functions from the shortcut menu.

Related Topics 

Setting the Reference Point

Drawing a Straight Line

Drawing a Spline

Drawing a Center-Point Arc Line

Drawing a Polyline

Deleting Polyline Segments

Converting Polyline Segments