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Problem with elminating nodes

Anonymous

Problem with elminating nodes

Anonymous
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I am relatively new at AutoCAD. I converted a .png image to a line drawing .dxf file in CorelDraw. I can open the .dxf in AutoCAD, however there are an overwhelming number of nodes in the line drawing. How do I eliminate the nodes but maintain the intergrity of the line drawing? From AutoCAD, I need to transfer the file to Sheet Cam, which then allows me to convert to a .tap file then to gcode. Then in Mach3 I open the gcode and operate my cnc plasma cutter.

 

Eliminating the nodes should create a smoother cut path. Thoughts?

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Kent1Cooper
Consultant
Consultant

@Anonymous wrote:

.... I converted a .png image to a line drawing .dxf file .... there are an overwhelming number of nodes in the line drawing. How do I eliminate the nodes but maintain the intergrity of the line drawing? .... Eliminating the nodes should create a smoother cut path. ....


Welcome to these Forums!

 

What do you mean by "nodes"?

 

If you mean Point entities [the things that the "node" object-snap mode snaps to], those can be eliminated easily by selecting them all with QSELECT, and ERASE-ing/Deleting them.  That would not interfere at all with the "integrity" of other drawing entities.

 

If you mean something like a high density of vertices along a Polyline, that you want to reduce the number of, there are routines that can do that, such as PLDiet.lsp with its PLD command, available here.  Or in new-enough versions of AutoCAD, you could Explode the Polylines and then use Join to re-connect them, in which there is an option to consolidate any collinear Lines into single Polyline line segments [or single Lines] -- PLD does that automatically to any series of vertices in a Polyline that are collinear.

 

If you mean something like kinks or bends in a Polyline with a lot of short line segments that you want smoothed out into curvature for "a smoother cut path," try PEDIT on it, and the Fit or Spline option.

 

Or do you mean something else?

Kent Cooper, AIA

Anonymous
No aplicable

First, thank you so much for the detailed answer. It helped me understand what I was actually trying to describe. It appears that I am referring to vertices. I attached an image of the project I'm working on. I was able to explode and I believe I was able to join but I was not able to locate consolidate. I'm using a 2016 student version of autocad. I also tried to get the PLDiet, but I didn't really understand what or how to deal with it. The only area I could download anything was 'download this tip' and when I opened it it looks like coding I would place somewhere, but not sure where.

 

 

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Kent1Cooper
Consultant
Consultant

@Anonymous wrote:

.... It appears that I am referring to vertices. .... I was able to explode and I believe I was able to join but I was not able to locate consolidate. I'm using a 2016 student version of autocad. I also tried to get the PLDiet, but I didn't really understand what or how to deal with it. The only area I could download anything was 'download this tip' and when I opened it it looks like coding I would place somewhere, but not sure where.


[I misled you in one thing -- the option to consolidate collinear Lines is not in the JOIN command as I mistakenly recalled, but in the OVERKILL command.  You can just use OVERKILL on the Polyline without Exploding it, and make sure the box for "Combine co-linear objects when aligned end to end" is checked.  That will remove excess intermediate vertices that are collinear.  But it looks from your image as though that isn't a likely situation.]

 

Put the PLDiet.lsp file in some known folder location, and in the drawing, type APPLOAD [or just its command alias, AP], navigate to where you put the file, and Load it.  Then the PLD command will be available.  Follow the prompts.  It looks, from your image, as though it can straighten most of those couple-or-several-segments-long edges of the leaf serrations, if you give it a maximum length that's a little longer than those, and accept the 15-degree default on the maximum change in direction to straighten, which will prevent it from removing the "teeth" points.

 

But I'm not sure whether that's really what you want to do.  A "smoother cut path" might mean you really want to replace those stretches with arc segments, rather than straighten them.  That could be tedious, but one way to do it would be to first PLD it to straighten them, and then pick the Polyline and go around [if you have a new-enough version of AutoCAD] hovering over the midpoint grips and choosing the "Convert to arc" option, and pulling the midpoints off a little to add some bulge.

Kent Cooper, AIA
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Anonymous
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Well although I have not been able to fix my particulr issue yet. Your information is very informative without a doubt. Well as luck would have it, I tried the APPLOAD method and I am unable to load PLDiet.lsp, I truly enjoy how extremly frustrating this has become. I bought a CNC Plasma cutting machine figuring I could just whip together some designs and cut some metal. I have quickly learned that is not the case by a long shot.

 

Regarding the file, when I follow the link you gave me the only thing I see that can be downloaded is labeled 'download this tip' and what I get is a file that looks like a notepad file as opposed to any type of app.

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Kent1Cooper
Consultant
Consultant

@Anonymous wrote:

.... I tried the APPLOAD method and I am unable to load PLDiet.lsp....

 

Regarding the file, when I follow the link you gave me the only thing I see that can be downloaded is labeled 'download this tip' and what I get is a file that looks like a notepad file as opposed to any type of app.


"Unable to load" isn't enough information....  Are you not able to locate where it went when you downloaded it?  If you can navigate to it, does APPLOAD say anything about why it doesn't load?  Not in a "trusted location," perhaps?  Is there some kind of error message about the loading?  It should leave you with a message at the Command line:  Type PLD to put PolyLines on a Diet.  Does it not do that?

 

It's a file with a .lsp filetype ending, which is an "app," if you want to call it that, for AutoCAD.  They're editable in text editors such as Notepad.

Kent Cooper, AIA
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Anonymous
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I have this exact same problem as mentioned by the author of the original post.

 

I have a pattern imported from vector in Adobe illustrator that I want to cut a pattern from on a CNC machine.

 

The machine is simplying dying because of the number of nodes/segments on the polylines. There has to be a way to merge these segments into a continous line, or atleast reduce them to a manageable number, without changing the original shape in the least. I do not want to smoothe the shape or reduce the vertices, simply want to merge all the segments into one coherent line.

 

I have been trying to find a solution for this without avail for the past couple of days. I want to say that it is almost ridiculous how difficult this seems to be. Is there really no solution to this?

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Kent1Cooper
Consultant
Consultant

@Anonymous wrote:

.... There has to be a way to merge these segments into a continous line, or atleast reduce them to a manageable number, without changing the original shape in the least. I do not want to smoothe the shape or reduce the vertices, simply want to merge all the segments into one coherent line.

....


I think you're out of luck there.  Polylines are the merging of multiple segments into one coherent [that's-why-it's-called-a-Poly-] line.  [Would your equipment work better if you Explode them into all the separate Lines/Arcs?]  You can't make it take less memory [if that's the actual issue] without reducing the number of vertices, which [except in the following situation] will necessarily change the original shape.

 

The only thing that might help is if some of those segments are collinear, and the intermediate vertices along the straight part(s) can be eliminated.  PLDiet.lsp [link in Post 2] will do that, if you give it zero for the maximum change in direction to straighten, so that it won't straighten any actual bends, and will therefore leave the original shape unchanged.  You can give it anything you want for the maximum distance between vertices to straighten, because it ignores that limitation in eliminating vertices between truly collinear segments.

Kent Cooper, AIA
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pendean
Community Legend
Community Legend
This is not the website to seek help with Adobe Illustrator (which creates heavy noded objects from broken lines connected together).
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steve216586
Advisor
Advisor

Why don't you take the time to re-draw the pattern using arcs instead of tiny line lengths, joined to create curves? You could eliminate thousands (x10) of vertices by doing this.

 

SMH

"No one can make you feel inferior without your consent. "-Eleanor Roosevelt
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Anonymous
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This is quite clearly NOT an Adobe illustrator issue which is why it is being posted here.

 

The vector drawing is imported from illustrator because in this particular case reproducing the original natively in AutoCAD is hundreds of man hours worth of work, if not thousands.

 

The question pertains to methods to reduce the number of nodes in a polyline while preserving the integrity of the line. How we got the line is not the issue here.

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Anonymous
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The vector drawing is imported from illustrator because in this particular case reproducing the original natively in AutoCAD is thousands of man hours worth of work. The formulas and blueprint to create the original do not exist anymore.

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Anonymous
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I tried PLD and it has helped a great deal actually. The problem is a lot more manageable now. Thanks!

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