What is wrong with these Polylines?

[abbas.baghernezhad]

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!

[cadffm]

Hi @abbas.baghernezhad 

Now I feel a bit stupid, but it can happen (only those who say nothing don't say the wrong thing) 🙄.

Thanks for the second example which brought me back on track.

I think the problem comes from the arc segments,
these are extremely minimally deviating from 90° and the
The assumption is that it leads to rounding errors in the program / a math problem.
If I correct the Arc data, Trim behaves as expected again,
or at least better than before, lol.

Ask:
Can you please explain to us how the polygon was created?
Which command, which inputs, please give us step-by-step instructions to follow.
What is particularly interesting here is the specification of the rounding,
i.e. how the arches were created.

I took one of you bot plines from the second 'sample.dxf'

please test it on your side.

[cadffm]

or were the polygons created somewhere else and you moved/copied/scaled them?

I'm looking forward to your instructions.

[abbas.baghernezhad]

No, Unfortunately that doesn't work.

[abbas.baghernezhad]

Thank You for your attention to the subject.

Pronest is a nesting software. We import the parts (polylines) as DXFs or DWGs and export nests. As a matter of fact I think you are right, parts comes out of Pronest with a slight difference in size and shape which is negligable in production process. for example a dimension of 100mm comes out as 99.9998 ot something like that. Or we never get our circles as circles! they are always exported as a polyline with 2 arcs. (a 90 and a 270 degrees arcs) We don't know what happens inside Pronest but the polylines are closed which means... they are not acutually 100% closed.
It is intersting!!!

Is there something we can do about it?

[cadffm]

Are my edited plines working?

Do you have 90° ONLY, or also other arc segments

[TheCADnoob · Accepted solution]

This is an interesting one... 

The only way i can duplicate any similar behavior with items i create is by creating a spline... its like a polyline is behaving like a spline in regards to trim. 

You can use boundary to create a new polyline. 

[abbas.baghernezhad]

Well Said! boundary works!