User Guide
User Guide
User Guide

Place Conic

Use it!

Used to place a conic section — a hyperbola, parabola, or partial ellipse — as a third-order uniform rational B-spline curve with three poles.

Tool SettingEffect
Type

Sets whether the conic section is a Hyperbola, Parabola,
see footnote 87 or Partial Ellipse.
see footnote 88

Define By

Sets the point defined in step 4 of the procedure below.

  • Points
    • — a point on the element is defined.
  • Tangents
    • — the intersection of the tangent lines is defined.
Rho

The range setting is variable for Hyperbola and Partial Ellipses only and its value depends on the Type:

  • If Hyperbola, 0.5 < ρ < 1.0

  • If Parabola, ρ = 0.5.

  • If Partial Ellipse, 0.0 < ρ < 0.5.

To place a conic section
  1. Select the Place Conic tool.

  2. Enter a data point to define one endpoint.

  3. Enter a data point to define the other endpoint.

  4. Enter a final data point.
    If Define By is set to Points, it defines the shoulder point.
    If Define By is set to Tangent, it defines the intersection of the tangent lines.

    Place Conic. Left: By Points; Right: By Tangent. Double-dotted curves are partial ellipses (0.0 < ρ < 0.5), solid curves are parabolas (ρ = 0.5), and single-dotted curves are hyperbolas (0.5 < ρ <1.0).

      

Key-in: PLACE CONIC