2011

Table Of Contents
Quick Reference
Commands
ELLIPSE
Creates an ellipse or an elliptical arc.
System Variables
ANGDIR
Sets the direction of positive angles.
PELLIPSE
Controls the ellipse type created with ELLIPSE.
Draw Splines
A spline is a smooth curve that passes through or near a set of points that
influence the shape of the curve.
The SPLINE command creates curves called Non-Uniform Rational B-Splines
(NURBS), which we will refer to as splines for simplicity.
By default, a spline is a blend of curve segments of degree 3 (cubic)
polynomials. Cubic splines are the most commonly used ones, and they
correspond with splines created manually using thin wooden strips shaped
by weights at data points.
For example, the SPLINE command was used to create one boundary of the
concrete walk that extends between the driveway and the house as shown.
Draw Splines | 281