dxf export settings

[laughingcreek]

I need to work with some DXF drawings that are exported from Rhino 5.  The curves import into fusion as a kajillion (roughly) lines.  Enough to actualy bog fusion done from a relativly simple sketch.  Does anyone have suggestions for what the DXF export settings in Rhino should be to get a better result when imported into Fusion?

[laughingcreek]

In an effort to figure this out, I've exported to a number of different DXF files with different export settings (From Rhino).  Problem is most all fail to up load.  I don't know if this is because of size, or if something is failing to convert, or what.

[innovatenate]

Could you share the DXF files with us? Have you tried bringing in the 3DM file from rhino directly? You might be able to do something like an extrude in Rihno to convert the curves to 3D and then upload file (as a rhino 3dm).

Thanks, 

[laughingcreek]

Hey Nathan-

The whole extrude to import thing is a nifty trick, but not really a workable solution.  Most anything I would need to import would be pretty difficult to work with in that way.  Would really like some guidelines on what Fusion is looking for when it imports.  

Most of the DXF files I have attempted to import so far have failed, but I've no idea why.  The ones that do import break the curves up into so many lines that it's imposable to work with.  I can do a certain amount of cleaning up of curves in Rhino, but that's not much use if the conversion process gives me all these little bits.  Also, directly importing Rhino files gives inconsistent results.  Sometimes part of the drawing, or nothing at all.  I can't seem to predict what will give me the result I want.

Here are some examples of what I need to get into Fusion.  These files come from someone I collaborate with from time to time.  They are always messy and usually require a bit of work before I can really start working with them.  Just the way it is.

This first one is the drawing file I receive.  The geometry is everywhere, and needs to be organized and repositioned before I can use it.  

http://a360.co/1zUNEHK

This is a Rhino file where I've deleted most of what is unnecessary, repositioned geometry, and organized a bit into different layers.

http://a360.co/1AZEaAx

This is a DXF of above file that fails to convert, but I don't know why.

http://a360.co/1MGABUj

[laughingcreek]

so I thought I'd try importing the various Rhino and DXF files I have for this project into Autocad.  Interestingly, they all come in with out a hitch.  and the splines are editable as splines, as I would expect, and not broken up into a bunch of short lines.  I've yet to find a good way to bring 2d geometry into fusion in a way that allows it to be readabley usable.  The cleanest method (meaning not having so many tiny lines that it actually bogs down fusion) has been extrude before import, and then project into sketches.  This method is cumbersome and doesn't yield geometry (splines, lines, etc.)  that can be manipulated.

So, is there just not a good way to get 2d curves into fusion?  Some guidance please.

[innovatenate]

Thank you for sharing the files. Have you tried using an SVG file? This is another 2D vector format that compatible with Fusion 360. 

The only other format is AutoCAD DWG format. I took the DXF file you shared, opened it in AutoCAD and used the Explode command on all the sketch figures. Next, I Imported this file into Fusion 360 and it seems to come in pretty nicely. 

http://a360.co/17ritNz

I'm still investigating the issue with the DXF. I do see some of the issues you mention above. It looks like some spline sketch geometry doesn't quite seem to come in as a "true" spline. I suspect this is working as designed for the moment, but I will check with development and circle back with you. 

For now, hopefully one of the above suggestions will help. Please keep us up to date on your progress.

Thanks,

[laughingcreek]

So apparently using the explode command is necessary.  Importing the above DXF still gives me an error, but if I open in autocad and explode first like you did, then I can import it.  I tried to explode and export directly from Rhino, but I still get an error that way.   It's not immediately obvious to me that exploding 2d geometry first before exporting to DXF (or that i would have to do it with autocad) would be necessary to get a good import.  If you hadn't said that's what you did, I probably wouldn't have tried it.  Yet another example of why well written, indexed documentation is so desperately needed for fusion.

Moving on...

FWIW-I hope splines not importing as working splines isn't really "working as designed."

Rhino unfortunatly doesn't have a SVG export option, so I haven't tried that.  I couldn't find the option in autocad either, does it have one?

Of course, importing the rhino files directly still seems to be a mess for 2d geometry.  I could work around that with the DXF output if I can get splines to behave.

[innovatenate]

I was just reading up on the Rhino site about Arcfitting for exporting to a laser.

http://wiki.mcneel.com/rhino/exporttolaser

It seems like you may be able to use the Convert command to specify lines/arcs, and to simplify some splines. Are you using this command?

This may be why you need to exploded the DXF/DWG file first in AutoCAD.

http://docs.mcneel.com/rhino/5/help/en-us/commands/convert.htm

You may also want to experiment with the converttobeziers command.

http://docs.mcneel.com/rhino/5/help/en-us/commands/converttobeziers.htm

I hope that helps. 

Thanks,

[laughingcreek]

Yes, I have tried converting splines to lines and arcs.  A machine that excepts a serial stream of tiny lines and arcs, such as a laser cutter or a cnc mill, handles such files just fine.  Fusion, however, does not seem to like having thousands of little lines, and bogs down.  Even if it didn't, I would prefer to work with a spline object rather than a bunch of short lines approximating my curve.

I looked at your link for the Rhino convert command.  I didn't see what you meant by why it may be the reason I have to explode in autocad first.  could you explain?

I tried convert to bezier curves.  much the same result.  Native Rhino file doesn't open in fusion with any 2d geometry.  DXF fails to convert. DXF opened in Autocad and exploded does convert.  The curves are somewhat editable, but only with the move command.  The curves are all broken into smaller segments, so getting clean curves is difficult.  And fusion seems to have to think about things for a min or so after each move.

So here's a question.  These files seem to open and play nice with autocad.  Why shouldn't they with Fusion?  

[laughingcreek]

Also, the DXF files that are just lines and arcs import into fusion without first exploding in autocad.  DXF files with splines and bezier fail to convert.  Not sure if that's sigificant.

[innovatenate]

I suspect what is happening here is that Rhino is converting your spline entities into polylines (PLINES) and squashing everything down into one layer. I believe corel draw is famous (or infamous) for doing the same thing. This is why exploding in AutoCAD helps. 

I know a lot of laser/plasma cutter programs will prefer a PLine over an actual spline figure. This enables an approximation of a spline within acceptable tolerances that greatly helps with the speed with which these tools do their jobs. 

From the DWG/DXF Export Options on the Rhino website, I'm not able to recognize what the right option may be to change this behavior. 

I note there are some Export Schemes. Have you tested using the 2004 or R12 "Natural" scheme? CAM Imperial?

http://docs.mcneel.com/rhino/6/help/en-us/fileio/autocad_dwg_dxf_import_export.htm

It seems that there is a way to create an ACADSchemes and create an AutoCAD export as well.

http://docs.mcneel.com/rhino/6/help/en-us/commands/acadschemes.htm

I'm guessing here, but I bet you would need to select the following curve options:

Rhino Object - AutoCAD Object

Lines            - Lines

Arcs              - Arcs             

Polylines       - Polylines         

Curves          - Splines

Polycurves    - Splines

Fusion 360 has a constraint based sketch environment that differs from AutoCAD or Rhino. There is a level of translation and mapping that needs to occur in order for a file to imported from ACAD or Rhino into Fusion 360. You may be able to help this mapping by tweaking the above settings.

I suspect at this time, there are a few work in progress items that are impacting the issue with the splines being editable after importing. I'm still looking into confirming this and will get back to you ASAP.

I hope this helps!

Thanks,

[laughingcreek]

I have tried every permutation I can think of for DXF export settings from Rhino.  For the drawing I'm trying to convert, the only ones that come in, without going through autocad first, are the DXF's that are converted to lines and arcs only. The original drawing was produced by someone with little cad experience, and no concept of good practice.  There's no telling what might be lurking in there.  So I started experimenting with a fresh drawing to see if I could nail down what is causing the problem for Fusion, but haven't had time to do much experimenting yet.  So far, the import behaviour doesn't seem to be as problematic for drawings I create myself.  Which is why I was hoping to get something more specific from fusion in terms of why the conversion fails.

When the DXF from Rhino is opened in Auto cad, all the geometry is located on the correct layers, so the idea that Rhino is squishing everything into a single layer doesn't make sense to me.

I do hope the issue with splines gets repaired.  Even a spline drawn and imported from autocad is not editable in fusion.

[HughesTooling]

This thread is a bit old but here's a link to a tips thread with a Rhino export scheme that works well so far.

Mark