三个点，两个斜率

Synopsis

obj = GCONIC/point1,point2,point3,VECT,x1,y1,z1,x2,y2,z2

Description

Creates a general conic by specifying three previously defined points and two vectors which represent the slopes of the conic at the first and last point.

Parameters

Parameter

Description

point1,point2,point3

Three previously defined points which are on the curve. All of the points must be coplanar, however, they may not be collinear. The points must be specified individually if an array is used.

VECT

Minor word that indicates that two tangent vectors are to be specified.

x1,y1,z1,x2,y2,z2

The six components of two vectors which may be specified individually, as two arrays, or any combination of the two. The specified vectors represent the tangents of the conic at the first and last points respectively.

Example

Creating a general conic through three points controlled by a beginning and ending slope.

Declaration

ENTITY/P(3),GC1

Geometry Definition

P(1)=POINT/1,1
P(2)=POINT/2,1.5
P(3)=POINT/3,1

Conic Definition

GC1 =GCONIC/P(1),P(2),P(3),VECT,1,2,0,1,-2,0

General Conic Using Three Points and Two Vectors

Parameter	Description
point1,point2,point3	Three previously defined points which are on the curve. All of the points must be coplanar, however, they may not be collinear. The points must be specified individually if an array is used.
VECT	Minor word that indicates that two tangent vectors are to be specified.
x1,y1,z1,x2,y2,z2	The six components of two vectors which may be specified individually, as two arrays, or any combination of the two. The specified vectors represent the tangents of the conic at the first and last points respectively.