'2D polyline' & 'polyline' What's the difference?

[seant61]

Have you got it set to 2? Did it convert when you opened the example I posted?

Where is that example?

[Dave F.]

Where is that example?

Err.... Should have been attached to message 4.

Here it is.

[seant61]

No automatic conversion here (2004). I guess it requires an explicit “Convert” (or “ConvertPoly” if LWPoly => 2DPoly required). PLINETYPE must only apply to polys created within the current drawing session.

I can’t make any suggestions other than the previously stated FIT/SPLINE issue. One thing I did notice with those PEDIT options; if the poly is straightened via PEDIT-DECURVE, it reverts to a LWPoly. If the curve is straightened via the Properties Window FIT/SMOOTH – NONE, it remains a 2DPOLY. Probably not germane to the OP, but interesting none the less.

[Coolmo]

FWIW, PEdit/Fit and PEdit/Spline turn a LWpolyline into a 2D Polyline (not a Spline) by curve-fitting.

It's still considered a "splined" polyline though... until you break, trim, or explode it.

[jaberwok]

It's still considered a "splined" polyline though... until you break, trim, or explode it.

True but not my point.

lwpolyline becomes 2dpolyline

[radunn]

Hi

I've got a combination of two types of entity - '2D polyline' & 'polyline'.in a dwg.

For some reason they display different context menus when I select them & right-click.
They were created the same way I think, individual lines joined using pedit.

I've got the PLINETYPE system variable set to 2 so they're all optimized to 2d.

When I use the CONVERT command it converts the '2d Polylines' into 'polylines'. Which is what I want.

However, I still don't understand how I created the '2D polylines' & why , having PLINETYPE set to 2 it didn't convert when I reopened the dwg.

I still don't understand what the difference between the two is. They have no Z values & are in the world UCS plain, just at different elevation, which, as I understand it, doesn't make any difference.

Any ideas?

Thanks for your help.

I have found that AutoCAD drawings that are exported from other products i.e. Inventor, create a lot of 2d Polylines. Converting 2d polys to polylines reduces file size dramatically.

Could this be the reason? After I run the convert command, I run "Overkill" which picks up (some of) the duplicates.

Roy

[mhaines.195717]

I have been having a similar problem, but this may be a separate thread. I am working in LT 2008 and the program spontaneously started making polylines with just one handle. Sometimes. I can draw several plines with no problem, then the next one has just one handle. I am picking the button on the tool panel, not doing anything different. Rectangles have one handle too.

I did't understand the discussion about pline vs wlpline although I did check that 'plinetype' is set to 2.
I should note that I am working on a Mac using Fusionware to toggle to windows so I can run AutoDAD. I'll try a reboot, that sometimes helps work out the Mac/PC culture clash.