User Guide
User Guide
User Guide

Construct Parabolic Fillet

Use it!

Used to construct a parabolic fillet (curve element) between two lines.

Tool SettingEffect
Distance

The distance between the points of tangency.

Type

Sets how the parabola is aligned:

  • Horizontal
    • — aligned with the horizontal view axis. Used in highway design to join intersecting grade lines. All IGDS parabolas are horizontal.
  • Symmetric
    • — aligned with the identified lines.
Truncate

Controls which line(s) are truncated.

  • None
    • — neither line is truncated.
  • Both
    • — both lines are truncated at their point of tangency with the fillet.
    see footnote 75
To construct a parabolic fillet
  1. Select the Construct Parabolic Fillet tool.

  2. Identify the first line.

  3. Identify the second line.

  4. Accept the fillet and truncations, if any.

    Construct Parabolic Fillet. Left: Horizontal. Right: Symmetric. “D” denotes distance. Truncate is set to Both.

      

Key-in: PLACE PARABOLA [HORIZONTAL | MODIFY | NOMODIFY] [MODIFY | NOMODIFY]

In 3D, both elements must be on the same plane to be filleted.

To place a B-spline curve in the form of a parabola, use the Place Conic tool in the Curves tool box.