topic Re: What is wrong with these Polylines? in AutoCAD Forum

What is wrong with these Polylines?

abbas.baghernezhad — Fri, 12 Jan 2024 14:52:01 GMT

These polylines come out of Pronest Software. I can't use trim on them. As you can see there is a symbol shown like it is not allowed to trim! If I make the polyline attribiute closed as "NO", the error goes away. I can't figure out why this happens and how to make the polyline cured! If I set closed as "Yes", the error comes back! the same happens for exploding and joining. It is very interesting to know what is wrong with these PLs!

Re: What is wrong with these Polylines?

Valentin_CAD — Fri, 12 Jan 2024 10:40:12 GMT

@abbas.baghernezhad ,

See if using the BURST command helps or post the drawing for all to troubleshoot.

Betreff: What is wrong with these Polylines?

cadffm — Fri, 12 Jan 2024 10:42:06 GMT

Hi,

If you had attached the DWG, then you could check
Without the DWG you can only look into the crystal ball 😉

Self-intersection polyline

I guess there are multiple parts of this polyline at the same place.

You cancheck this by steping tthru the vertices or simple:

Explode it and use a cross/crosswindow sleection to check the exploded result at this point.

Is it just one line or multiple objects?

Share your DWG and we can stop guessing 🙂

Re: What is wrong with these Polylines?

pendean — Fri, 12 Jan 2024 14:06:08 GMT

@abbas.baghernezhad wrote:

These polylines come out of Pronest Software....

Did you try to find out if that software offers other export options that can fix the problem? They might have an idea or two as well

https://www.hypertherm.com/en-US/contact-us/technical/

https://www.hypertherm.com/en-US/contact-us/

Re: What is wrong with these Polylines?

Kent1Cooper — Fri, 12 Jan 2024 14:39:42 GMT

The command-line history showing in the image indicates that there must be some cutting edge(s) selected by Fence, but they are not apparent in the image [nothing highlighted, including the Polyline itself]. If:

A. the Polyline is not a cutting edge itself, and does not cross any selected cutting edge(s), or:

B. the Polyline is closed and only one cutting edge penetrates into but not through it;

then you would get exactly this effect -- you can't Trim the Polyline under those conditions, whether or not it comes from some other software. Could something like that be what's going on?

Betreff: What is wrong with these Polylines?

abbas.baghernezhad — Fri, 12 Jan 2024 15:10:17 GMT

I had prepared a sample. I did upload it... I don't know Why it wasn't there.
I uploaded it again!

sometimes there is a line with lenght of zero in the polyline. sometimes there are not any weired object. But even if you delet that zero lenght line and joint the rest, the problem insist to exist! (try the long polyline in the sample)

Re: What is wrong with these Polylines?

abbas.baghernezhad — Fri, 12 Jan 2024 15:03:09 GMT

We have just polylines. I guess BURST works on blocks only.

Re: What is wrong with these Polylines?

cadffm — Fri, 12 Jan 2024 15:27:05 GMT

Hi,

If you don't have "valid" cutting edges objects(or segments), you can't cut(trim). That's all?

I could find any problem in the file/polyline.

BTW: If you want to erase a segment from your plines, [CTRL]+[LMB] and [DEL]

last or/and next segments tangential, is not two valid cutting edges, because they are not crossing each other

Re: What is wrong with these Polylines?

abbas.baghernezhad — Fri, 12 Jan 2024 15:33:06 GMT

I'm sorry if there was no sample uploaded. There it is.

These polylines are closed.

Re: What is wrong with these Polylines?

pendean — Fri, 12 Jan 2024 15:36:58 GMT

@abbas.baghernezhad Where is this in your DWG file?

Re: What is wrong with these Polylines?

abbas.baghernezhad — Fri, 12 Jan 2024 15:45:45 GMT

somrtimes using [CTRL]+[LMB] and [DEL] on these PLs leads to deleting the whole polyline. Not always possible!

do we need "valid cutting edges" to use trim or [CTRL]+[LMB] and [DEL] on PL segments? and what is a "valid cutting edge" ?

Re: What is wrong with these Polylines?

Kent1Cooper — Fri, 12 Jan 2024 15:51:46 GMT

@pendean wrote:

....Where is this in your DWG file?

Did you open the wrong file? I get this with the file at Message 9:

Re: What is wrong with these Polylines?

abbas.baghernezhad — Fri, 12 Jan 2024 15:47:31 GMT

Sorry again!

Re: What is wrong with these Polylines?

cadffm — Fri, 12 Jan 2024 15:54:51 GMT

This is TRIM command, not Break! You need 2 cutting edges (say trim edges) to trim something.

A tangential curve is NOT an intersetions

https://help.autodesk.com/view/ACD/2024/ENU/?guid=GUID-B1A185EF-07C6-4C53-A76F-05ADE11F5C32

Re: What is wrong with these Polylines?

cadffm — Fri, 12 Jan 2024 16:03:07 GMT

And regardless,
you cannot completely trim the first segment of a polyline

and also not the closing segment (which you can't see in your example because you have drawn an unnecessary point)

Re: What is wrong with these Polylines?

pendean — Fri, 12 Jan 2024 16:16:58 GMT

@Kent1Cooper wrote:

@pendean wrote:

....Where is this in your DWG file?

Did you open the wrong file? I get this with the file at Message 9:

Message 1...

Re: What is wrong with these Polylines?

pendean — Fri, 12 Jan 2024 16:32:28 GMT

@abbas.baghernezhad How much more time do you want to mess with this?

Do this: EXPLODE your PLINEs then remake them into PLINEs again (there are dozens of free LISP to do the latter all over the web). All of your problems go away. Took less that 10-15 seconds in each of your two different DXF files posted in this thread.

You issue(s) has all to do with hat other software. Sorry, AutoCAD can't auto-fix them for you.

Best wishes.

Re: What is wrong with these Polylines?

abbas.baghernezhad — Fri, 12 Jan 2024 18:34:04 GMT

test trim on the attached sample. It is possible to trim every segment!

Re: What is wrong with these Polylines?

abbas.baghernezhad — Fri, 12 Jan 2024 18:39:07 GMT

Unfortunately explode and join Doesn't work!

I'm curious about this problem. It is stange. There is sth important about polylines that we are missing.

Re: What is wrong with these Polylines?

Kent1Cooper — Fri, 12 Jan 2024 18:55:21 GMT

@abbas.baghernezhad wrote:

Unfortunately explode and join Doesn't work!

....

If you Explode and then Erase the zero-length Line that results at the original start/end points where you have coincident vertices, and then Join, does it work?