Trim b-spline Data Type

Declaration:

ttbs ( ctype = <scalar>, dim= <scalar>, m= <scalar>, n = <scalar>, rat = <scalar>, form = <scalar>, <trim_control_vertex_list> )

Literal:

te( ctype = <scalar>, dim= <scalar>, m= <scalar>, n = <scalar>, rat = <scalar>, form = <scalar>, <trim_control_vertex_list> )

Purpose:

This defines a trim b-spline. A trim b-spline may be specified as a literal. A trim b-spline has seven arguments.

ctype	the type of b-spline; general (0), line (1), parabola(2), circle(3), ellipse (4), hyperbola (5), or C2 cubic (10).
dim	the dimension of the trim b-spline.
m	the degree of the spline.
n	specifies the number of spans.
rat	specifies if the curve is rational (1), non-rational (0) or homogeneous (-1)
form	describes the type of edge; 0 is open, 1 is closed, 2 is periodic, and -1 is disjoint.

The last argument is the list of two or more trim curve vertices that define the trim b-spline

Limitations:

The elements of a trim edge (see Trim edge Data Type) must be literals. They may not be represented by expressions or variables.

Example:

tbs(ctype = 0,dim = 2,m = 3,
	n = 1,rat = 1,form = 0,
	tcv(0.9501376,-2.6293772,1.0,0.0),
	tcv(0.9514360,-2.6064462,1.0,0.08	),
	tcv(0.9519445,-2.5832916,1.0,0.08),
	tcv(0.9519445,-2.5600670,1.0,0.08)
)