Graphics Programs Reference
In-Depth Information
Arcs cannot be joined to elliptical arcs.
•u
Arcs must have the same center point and radius but can have a gap between the segments
•u
you wish to join. The same is true for elliptical arcs.
Lines must be collinear but there can be gaps between the lines to be joined.
•u
Unless you are joining to a polyline or 3D polyline, objects must be on the same 3D plane.
•u
SKETCHING WITH AUTOCAD
AutoCAD offers the Sketch command, which lets you do freehand drawing. If you have access to a
drawing tablet, you might give the Sketch command a try. Here is a brief description of how you
might use it:
1 .
Enter
SKETCH
↵.
2 .
Enter
T
↵
S
↵ to use a spline for your sketch object.
3 .
Start drawing your freehand lines. Temporary sketch lines will appear in the drawing.
4 .
Press ↵ when you are finished. The temporary lines will be replaces with splines.
If the spline curve doesn't look right, you may have to set the tolerance setting for the Sketch com-
mand. When using splines for sketch objects, the tolerance option sets the distance between control
points for the spline. To set the spline tolerance for the Sketch command, do the following:
1 .
Enter
SKETCH
↵
2 .
Enter
L
↵, and then enter a value for the sketch tolerance. You can start by using a value that is
slightly different from the default 0.5000. A lower number sets a tighter tolerance and the spline
will fit closer to your temporary sketched line. A higher value “loosens” the tolerance and the
spline will follow a smoother curve.
3 .
Start drawing your freehand lines.
If you'd like to know more about Sketch, refer to the AutoCAD Help system; it offers an excellent
description of how Sketch works.
Fine-Tuning Spline Curves
Spline curves are different from other types of objects, and many of the standard editing com-
mands won't work on splines. AutoCAD offers the Splinedit command: Choose Modify
Object
Spline or type
SPE
↵.
C
O N T R O L L I N G
T H E
F
I T
D
A T A
O F
A
S
P L I N E
The Fit Data option of the Splinedit command lets you adjust the tangency of the beginning and
endpoints, add new control points, and adjust spline tolerance settings. To get to these options,
follow these steps:
1.
Choose Modify
Object
Spline, or type
SPE
↵ at the Command prompt.
2.
At the Select spline: prompt, select the last spline you drew in the previous exercise.
