The features available from the Create>Conic pull-down and palette submenus allow you to create Conic, Ellipse, and Parabola geometry.

• A conic is a special curve generated by a point, which always moves so that the ratio of its distance from a fixed point to its distance from a fixed line is a constant. Conic creates conic sections by indicating two, three, four, or five positions that the entity passes through. If the conic is a hyperbola, the first and last positions that you indicate must be on the same branch.

The conic functions, with the exception of By 6 Coefficients, will behave differently depending upon the active construction mode Z lock or Z Free(2D or 3D). The 2D/3D Z Lock switch and the current construction plane are read when the first position is selected. The conic is created based on these values. It is not recommended that you change the Z Lock switch, or the active cplane, once you have selected the first position. The code paths and data stored are different enough to make such an action impractical. This does not apply to ellipse or parabola entities.

• An ellipse is a set of points within a plane where the sum of the distance between one fixed point to any two other fixed points is constant. There are three ways to create an ellipse: by Values and Outer or Inner Axes.

• A parabola is a set of points in a plane, with the condition that the distance from any point in the set to a given line, the directrix, is equal to the distance from that point to a given point, the focus. A parabola is created with a defined directrix, focus, and start and end points for the entity. The focus cannot be on the directrix.

To view information on a feature available from the Create>Conic submenu, click on the appropriate link below:
Ellipse by Values
Ellipse by Outer Axes
Ellipse by Inner Axes
Parabola from 2 Positions
Parabola from Line
Parabola from EndEnt
Conic from 2 Positions
Conic from 3 Positions
Conic from 4 Positions
Conic from 5 Positions
Conic from 6 Coefficients