Hi,
Can anyone please tell me the difference between Polyline and 2D Polyline
and where we can use them?
Thanks
|
Hi,
Can anyone please tell me the difference between Polyline and 2D Polyline
and where we can use them?
Thanks
AFAIK, the PLINE command generates the 2D Polyline (technically called LWPolyline) and as the name indicates, it can be drawn only in 2D. That means, suppose you are drawing a LWPolyline in XY Plane, you can not draw it to the Z axis on the go. On the other hand, 3DPOLY command generates the 3D Polyline (technically called Polyline) which can be drawn in any direction (XYZ). 2D polyline is good enough for drawings in 2D and 3D polylines can be used in places like 3D extrution path, for example.
sandeepk
http://forums.augi.com/showthread.php?t=75919
This may help, or then again, it may not! it confused me!.
The original Polyline in AutoCAD while a vast improvement over having to use line segments and arcs was a resource hog. each vertex and end were separate entities so a Polyline with two vertexes was four entities. In r14 AutoCAD introduced the lwpolyline (lightweight polyline) which was a single entity. For drawing which included lots of contours or other complex polylines drawing sizes shrank considerably. Big difference in speed and stability as well.
In conclusion both represent the same thing, but the newer lwpolyline is a major improvement. If you are encountering old "Heavy" polylines you may be getting them from another program that claims to output AutoCAD entities. Sadly many of these programs have not been updated in quite some time. The AutoCAD Convert function does a nice job cleaning them up though.
Here is some more information on the topic, I hope it doesn't make all this even more confusing...
R.K. McSwain | CAD Panacea |
Thanks for that post.
OK, I'm still not 100% sure about this but from the Help:
PLINETYPE = 2
Polylines in AutoCAD Release 14 or older drawings are converted when opened; PLINE creates optimized polylines.
I think this is incorrect. I don't think they are converted when a dwg is opened.
Also is there a difference in ConvertPoly & Convert>polyline?
ConvertPoly isn't even listed in the '07 help!
Are you testing this with an R14 or older drawing?
If I recall correctly, Convert>Poly only converts "heavy" polylines to "Lightweight" ones, while "ConvertPoly" lets you go either direction. ConvertPoly has always been an undocumented command.Originally Posted by Dave F
R.K. McSwain | CAD Panacea |
Thanks all,
But I can't understand the advantages of 2dpolyline ...