Draw Splines (Concept)

AutoCAD 2008 User's Guide > Create and Modify Objects > Draw Geometric Objects > Draw Curved Objects >

Draw Splines

Concept

Procedure

Quick Reference

A spline is a smooth curve that passes through or near a given set of points. You can control how closely the curve fits the points.

The SPLINE command creates a particular type of spline known as a nonuniform rational B-spline (NURBS) curve. A NURBS curve produces a smooth curve between control points.

You create splines by specifying points. You can close the spline so that the start and endpoints are coincident and tangent.

Tolerance describes how closely the spline fits the set of fit points you specify. The lower the tolerance, the more closely the spline fits the points. At zero tolerance, the spline passes through the points. You can change the spline-fitting tolerance while drawing the spline to see the effect.

You can use two methods for creating splines:

Create spline curves with the Spline option of PEDIT to smooth existing polylines created with PLINE. Such spline-fit polylines are created with uniform knot vectors and are more likely to be included in drawings created with earlier versions of the product.
Create splines, which are NURBS curves, with SPLINE. Drawings containing splines use less memory and disk space than those containing spline-fit polylines of similar shape.

You can easily convert spline-fit polylines into true splines with SPLINE.