cannot convert a POLYLINE to a LWPOLYLINE

[KevinMacDonald]

This is such an old and tired subject with a billion answers on the forums. And yet, nothing works for me.

The attached file contains a single POLYLINE. I would like to convert it to a LWPOLYLINE, so that I can then use the wonderful PLDiet.lsp routine on it to reduce the number of points.

CONVERT will not convert it.

CONVERTPOLY will not convert it. 

Ideally, I would like to be able to convert ALL POLYLINE objects in one go to LWPOLYLINE objects.

Can anyone provide precise instructions?

Thanks

[KevinMacDonald]

I have also tried FLATTEN. If I indicate YES to the "Remove Hidden Lines" option it does in fact turn a POLYLINE into a LWPOLYINE. But, it takes what was a nice smooth POLYLINE and turns it into jagged LWPOLYLINE. I need to be able to preserve the appearance.

[Patchy]

x

[devitg]

@KevinMacDonald Hi , the main fact is that it is a "AcDb3dPolyline" whose  Z value are not constant to any value. 

do you want to be all Z to  0 (zero)??

[KevinMacDonald]

My reason for wanting to get away from polyline is because it is
problematic extruding them into 3D objects. A 'Closed' LWPOLYINE is
generally what I need. Sometimes FLATTEN or FLATSHOT get me to where I
need, but not consistently. I'm often importing art work from Illustrator
and it is kind of a garbage clean up process. A lot of times Illustrator
will give me Splines, and the PEDIT command converts those to polyline not
LWPOLYINE.

[devitg]

@KevinMacDonald 

Hi , please check it .

[devitg · Accepted solution]

@KevinMacDonald How about it ?