Illustrator has many problems (video)

[cynd11]

I tried to reproduce your issue using my older copy of Illustrator (CS5) to see if it was a version issue. I couldn’t even open the dxf file; I get the following error message:

My version of DxfDwg.aip is 15.0.2; I don’t know what the current version is. Adobe’s support site was no help at all. If there is an update to this file they have it cleverly hidden.

I did notice on Adobe’s support site the following:

Importing AutoCAD files

Note:

Illustrator will not open AutoCAD files saved in a version later than AutoCAD 2007.

AutoCAD files include both DXF and DWG formats. You can import AutoCAD files from version 2.5 through version 2007. During import, you can specify scale, unit mapping (custom unit for interpreting all the length data in the AutoCAD file), whether to scale lineweights, which layout to import, and whether to center the artwork.

[Hirudin]

That’s funny! Frickin’ SolidWorks did the same thing. SolidWorks is kinda a piece of crap a lot of the time.

[dwardio]

No idea if this is relevant, but when learning to use vCarve/Aspire about a year ago at a makerspace, they made a big deal about setting all your software to use the same DXF version and they recommended R14. Seems to have worked with everything I’ve used since.

[dan_berry]

I think that this is a limitation with MANY of the DXF exports I’ve seen. I’ve imported DXF files into Sketchup, and beziers are always segmented. Sketchup also does curves in segments, but at least you can control it until you “explode” the curve, or convert the curve into a polygon.

It’s annoying that more programs don’t handle Beziers correctly, if at all.

[jdodds]

For what it’s worth, the same issue exists in the even older CS4 version of AI.

[Jules]

Well…I think i figured out a quick way to fix the segmenting in Illustrator. (Still haven’t taken the time to search through F360 to see if there’s a setting we can change.)

Select all of the curved paths (you can actually select everything, it doesn’t hurt linear constructs) then click on Object > Path > Simplify. Make sure the percentage is set to 100% on the slider.

If you do it a second time, it removes more nodes, but you start to get some very small wobbles in the lines, so you might want to stick with just doing it once.

It converts the straight segments to curves.

[Brandon_R]

If it hasn’t been done yet, I can try it on CC at work if you like.

[pomwah]

Inkscape gave me the same result as @smcgathyfay’s import to Corel

[ccox]

DXF is limited to lines, not curves.

[dan_berry]

@ccox

DXF is limited to lines, not curves.

It depends on the version of DXF and the support of the software’s import / export.

You can create a bezier drawing in Inkscape, save it as DXF, and then import it as a sketch retaining the bezier points into Fusion 360. I’ve done it myself, just now.

What people are discovering is that Illustrator’s export is translating the bezier into segmented line polygons, not into actual curves.

I’d suggest people try saving the Illustrator drawing as an Illustrator-native format (“.AI” version 9 or newer?) that Inkscape can open. If Inkscape keeps the beziers, save it to DXF and import that into Fusion 360.

[jkopel]

All this is true.
Just to note, @Hirudin was going in the other direction (from Fusion360 -> Illustrator), which means the import only understands line segments as well. It is unfortunate, but that is a choice the programmers made.

I would also add that it may not matter so much for laser cutting as long as the line segments are short enough and you don’t intend to manipulate the line much in Illustrator. If you do need to edit it then you can always turn it into a curve again, although it may be labor intensive.

[Jules]

@jkopel

If you do need to edit it then you can always turn it into a curve again, although it may be labor intensive.

Not too bad actually…figured that bit out here in post #16:

Illustrator has many problems (video)

Well…I think i figured out a quick way to fix the segmenting in Illustrator. (Still haven’t taken the time to search through F360 to see if there’s a setting we can change.) Select all of the curved paths (you can actually select everything, it doesn’t hurt linear constructs) then click on Object > Path > Simplify. Make sure the percentage is set to 100% on the slider. If you do it a second time, it removes more nodes, but you start to get some very small wobbles in the lines, so you might w…

[Hirudin]

I bet the converted curve would not perfectly match the original though.

[Jules]

It’s pretty close.

In order to test it, I copied the segmented paths and set them to one side before converting just that copy to curves. When laid over the original, it was an “exact” match.

(Obviously not absolute exact, but close enough for engineering work.)

[jbv]

So, if the same thing happens in Corel and Inkscape, it seems to me that this is a DXF versioning/translation problem, not an illustrator problem per se.

I saw paid 3rd-party add-ons and plug-ins for Ai that are supposed to solve this issue. Haven’t found a free solution.

[Hirudin]

It would be interesting to bring that curve back into Fusion 360 (or Rhino), extrude it, and then do a boolean subtraction between the two bodies.

I’d say if it’s not perfect it’s not up to engineering standards, but I’m not an engineer so maybe I’m not qualified to make that call.

[Hirudin]

It works in Rhino and Silhouette Studio though.

I’d kinda trust Autodesk Fusion 360 to make propper DXFs.

(the release of Rhino that I have, v4, was last updated in 2011, IIRC)

[jbv]

Yeah, Me too. But clearly there is an issue somewhere along the line.

Here is what I think I understand so far:
(correct me if I am wrong)

• There is vector/shape information, which is being read by all the programs.
• The bezier info is there, and can be read by some programs.
• The Fusion DXFs have unexpected properties (the extra lines and the flipped orientation).
• There have been several iterations of DXF, and they don’t always play nice with each other.
• Ai has many more options when exporting DXF than when importing it
• Fusion has no options when exporting DXF

[jkopel]

The history of the DXF file format is long (>30 years!), convoluted, and muddy.
There are LOTS of different versions of DXF, they are not interchangeable, and every program (even the various Autodesk programs) supports them differently.

You have to remember that it started as a way to exchange 2D CAD drawings and has grown “organically” over the years. Lots of other stuff has gotten smooshed in there, and the way drawing, CAD, or modeling programs work (i.e. how they describe a drawing) has changed as well.

If it works well enough to make my part and the part fits, then great. If not I have to seek out a different workflow.
(sad shrug)

http://images.autodesk.com/adsk/files/autocad_2012_pdf_dxf-reference_enu.pdf

[jamesdhatch]

@jkopel

There are LOTS of different versions of DXF, they are not interchangeable, and every program (even the various Autodesk programs) supports them differently.

SVG is like that too