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Valued Contributor
MetroVancouverDrafting
Posts: 66
Registered: ‎06-29-2010
Message 1 of 11 (217 Views)

Arcview broken arcs to true arc

217 Views, 10 Replies
04-19-2012 03:33 PM

When importing Shape files from Arcview/ArMap to Autocad you will find that all yor arcs were converted to the series of lines.

Now the question is how to convert them back to the true arc.

 

I wrote some lisp to address it, but you have to do a lot af manual work before use it and it is sooooow

The lisp is inside of the cad file, just copy/paste to command line.

I will stuck after about 5 min, just kill it Ctrl+Breack or Esc.

 

is anybody has a better solution, cause mine is not solution at all. If I'll start to improve it and analyse dipper it'll get even slower.

*Expert Elite*
antoniovinci
Posts: 1,575
Registered: ‎06-03-2011
Message 2 of 11 (209 Views)

Re: Arcview broken arcs to true arc

04-19-2012 10:49 PM in reply to: MetroVancouverDrafting

Since the shapefile format does NOT support arcs, you'd simply _MAPCLEAN your drawing - see the attached .DWG based on your data.

Valued Contributor
MetroVancouverDrafting
Posts: 66
Registered: ‎06-29-2010
Message 3 of 11 (201 Views)

Re: Arcview broken arcs to true arc

04-20-2012 08:04 AM in reply to: antoniovinci

Thanks for reply

 

Now, how do you convert an polyline in cul-de-sac, that used to be an arc, back to arc?

Valued Mentor
parkr4st
Posts: 412
Registered: ‎03-24-2004
Message 4 of 11 (183 Views)

Re: Arcview broken arcs to true arc

04-21-2012 02:36 AM in reply to: MetroVancouverDrafting

why do you need the arcs?  the polyline endponts define the arc.  set of points equidistant from a point.  on the ground you will locate the points to define the arc.  is it for good looks on the screen?

 

dave

Valued Contributor
MetroVancouverDrafting
Posts: 66
Registered: ‎06-29-2010
Message 5 of 11 (170 Views)

Re: Arcview broken arcs to true arc

04-23-2012 08:26 AM in reply to: MetroVancouverDrafting

Why do I need the arcs? 

Well, let me see, I am a small lines chauvinist. I hate these lines, they are short and ugly too. They are so small, that you can't really see them when they are alone. But as they get together they think they are important, they pretend to be the ARC.

 

sorry

*Expert Elite*
Alfred.NESWADBA
Posts: 8,866
Registered: ‎06-29-2007
Message 6 of 11 (167 Views)

Re: Arcview broken arcs to true arc

04-23-2012 08:29 AM in reply to: MetroVancouverDrafting

Hi,

 

if you want to have ARCs in AutoCAD, you will have to use another fileformat for dataexchange between ArxXXX and AutoCAD.

What about DXF, have you tried it?

 

- alfred -

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Alfred NESWADBA
Ingenieur Studio HOLLAUS ... www.hollaus.at
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Valued Contributor
MetroVancouverDrafting
Posts: 66
Registered: ‎06-29-2010
Message 7 of 11 (162 Views)

Re: Arcview broken arcs to true arc

04-23-2012 09:12 AM in reply to: Alfred.NESWADBA

Unfortunately I don’t have any other data, just a shape file, that why im trying to fix it in Autocad.

*Expert Elite*
Alfred.NESWADBA
Posts: 8,866
Registered: ‎06-29-2007
Message 8 of 11 (159 Views)

Re: Arcview broken arcs to true arc

04-23-2012 09:25 AM in reply to: MetroVancouverDrafting

Hi,

 

>> Unfortunately I don’t have any other data

Ok, but you have ArcView or ArcGIS, thinking that because of your first message:

>> When importing Shape files from Arcview/ArMap

 

So what happens if you open the SHP in ArcGIS ... do you really have arcs there?

If so (what I don't beleive, but am interested in that) you can try to export it as DXF and open the DXF in AutoCAD then.

 

- alfred -

 

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Alfred NESWADBA
Ingenieur Studio HOLLAUS ... www.hollaus.at
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Valued Contributor
MetroVancouverDrafting
Posts: 66
Registered: ‎06-29-2010
Message 9 of 11 (158 Views)

Re: Arcview broken arcs to true arc

04-23-2012 09:29 AM in reply to: Alfred.NESWADBA

You are right, I do have ArcGis but the datafile is a Shape. So even if it open it ArcMap it is still segments

*Expert Elite*
Alfred.NESWADBA
Posts: 8,866
Registered: ‎06-29-2007
Message 10 of 11 (155 Views)

Re: Arcview broken arcs to true arc

04-23-2012 09:38 AM in reply to: MetroVancouverDrafting

Hi,

 

well (or not), but in that case you have either luck and find such a tool in the www or you would have to spent some time (or money) for developing it.

 

It's not as hard as long as the segments are short enough and equal in length. Short enough for an automatism to recognize them as arc-segments and not as normal straight segment.

 

What may be more expensive is to take care of topology consistence for polygonal topologies. As polygonal shapes are defined by closed outlines there are always two polylines at the same position, so also the arcs. Now the worst case is that you calculate for each of these two neighbouring two arcs that are not exactly euqal. A minimal different radius or start- or endpoint could damage the topological correctness of your geometry.

 

Good luck, - alfred -

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Ingenieur Studio HOLLAUS ... www.hollaus.at
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