Importing CAD files..

[Mike Zagorski]

What is the best way to import CAD files into InDesign?

Is PDF the best way? It seems to get my machine crawling on its knees (512 RAM)

Mike

[FJK]

> What is the best way to import CAD files into InDesign?
>

If the files are in AutoCAD DWG / DXF format try the following:

1. Open the CAD file in Illustrator* and make any necessary changes.
2. Save it as AI or EPS.
3. Import this in InDesign.

*) This can take several minutes depending on the complexity of your CAD
drawing.

Just my 2p,
Franz-Josef

[Bob Levine]

Have you tried EPS?

Bob

[Joyce Murphy]

I use pdf when importing files from Visual Cadd. It helps to close the preview window in the CAD program when printing to pdf. Not sure if this applies to CAD programs other than Visual Cadd.

Joyce

[r_harvey]

DWG is a native AutoCAD format. DFX is their exchange format. The obvious answer, and the one I've tried, is Adobe Illustrator to import for InDesign; it can (mostly) read either CAD format. From our side, AutoCAD may use lots of short segments instead of graceful curves, and it's full of peculiar layers that you will probably want to hide.

A more important problem is that Illustrator 9 doesn't recognize CAD dimensions, so the imported image will be a postage stamp that you'll have to resize.

If your CAD program can export usable PDF, as Joyce mentioned, it should be easier than using Illustrator.

[Chad Cook]

The best way that I found was to use Distiller to print to PDF. This way you can set you preferences to prepress settings or any other that may suite you. I do this on a daily basis for a 1500 page catalog for the RF Microwave industry.

[Mike Witherell]

I was just speaking with a colleague from a federal mapping agency who says that Avenza Map Publisher is a great tool in converting to PostScript. Just passing that thought along, because again, I haven't worked with it. Here is the site address:

<http://www.avenza.com/products.mapub50.html>

Mike Witherell

[Ben Dupre]

Depending on where your CAD files are coming from, you're probably in for lots of troubles. Typically CAD systems export to DXF or EPS or PDF by chopping up the geometry into billions and billions of line segments. DXF does not support a particular type of CAD entity known as a spline and so the CAD programs approximate when exporting. This doesn't explain why the same thing happens in EPS and PDF exports because both of those programs support the familiar 3rd order bezier curves (which are more accurate than quadratic splines). Usually, CAD programs take the shortcut of letting Windows graphics facility render the file (this also happens when using cut-and-paste) before exporting and that will booger the geometry also.

At the core of the issue is the fact that CAD software vendors don't see far enough down the road to realize how their geometry will be used. If they can display on the screen and plot to paper their work is done. Millions of man-hours are wasted because CAD software programmers think their only customers are engineers.

By the way, you're best bet is to get the CAD software to write a release 13 (not higher) DWG file and open it using Illustrator, then save it as EPS or PDF from there. CAD software will usually create better geometry when translating into DWG than DXF, and Illustrator has a pretty good import filter.

Ben

[Carl B. Johnson]

> By the way, you're best bet is to get the CAD software to write a release 13 (not higher) DWG file and open it using Illustrator, then save it as EPS or PDF from there. CAD software will usually create better geometry when translating into DWG than DXF, and Illustrator has a pretty good import filter.

I have my engineers convert the CAD to DXF in vs. 14 (lowest we have the
capability to save back to, they tell me) and use Corel Draw to tweak
line thickness, etc. If you are going to print, then you will need to
beef up the lines unless you did that in ACAD already. Then I export to
TIFF or EPS depending on destination, and use those files. For ID, use
the EPS.

--
Carl B. Johnson
~~~~~~~~~~~~~~~~~~~~~
Respectibility in art is appalling.
www.wuli.com

[Carl B. Johnson]

> with Illustrator, you can simplify all the curves in a drawing in one fell swoop, reducing control points (nodes) by up to 80 to 90 % and reducing file size by the same proportion.

How do you do this? I may have to use the same workflow. I love Draw's
extremely competent Find/Replace>Outline Pen Properties which surpasses
anything I have been able to do with Illy. But Draw's Auto Reduce Nodes
selection when I open a DXF doesn't do all that well, I still end up
with a bloated mess at times.

[Ben Dupre]

CorelDraw works pretty good. I actually prefer it to illustrator, but Illustrator's import filter is a little more sound. AND with Illustrator, you can simplify all the curves in a drawing in one fell swoop, reducing control points (nodes) by up to 80 to 90 % and reducing file size by the same proportion. I usually do this, then save as AI and open in CorelDraw for modifications.

You can't simplify more than one curve at a time in Corel and with drawings upwards of 10,000 entities, who'd want to click each one? It can be scripted but even then it's take hours. I'm absolutely amazed that Illustrator can acomplish this in minutes or seconds.

Ben

[Mike Zagorski]

Thanks for all the replies. After a lot of time spent banging my head against the wall... Printing to an EPS file from AutoCAD using Postscript 2 did the trick. It was the only method that I could find that would give me output to the exact millimetres (Distiller failed at this many times despite 2 days of messing with it and reading lots of forums!)

AutoCAD -> EPS at Exact Size of Page -> InDesign (imports to scale without a problem and retaining good quality)

Another step is to go from EPS -> Illustrator to add colour to CAD -> InDesign.. but I've not quite mastered retaining the scale when AI is thrown into the workflow. I got it close using the Make PDF Script... but it was still about .5mm off which aint much - but still irritating :)

Mike

[Ben Dupre]

V:

In Ill 9 it's:

Object | Path | Simplify

You can select the entire drawing and simplify everything at once. You'll probably want to slide curve precision all the way to 100%, I don't use the angle setting.

I really recommend using an R13 DWG file going into Illustrator. DXF will have all splines broken up into segments, in DWG these segments will at lease be joined into common paths that can then be simplified as described above. If you have Ill 10, you might be able to use a newer version DWG. Ill 9 won't read R14.

Mike:

You can do that and it works, but you'll find your EPS file is larger than need be. If you have to do any editing in Illustrator, you'll also find that the neat exact geometry of the CAD program has been replaced by many many many little tiny scribbles. This makes simple tasks like changing line colors difficult, and forget about changing line thicknesses. Also, your text (if any) may be rendered to drawing shapes and no longer editable. See my earlier post for why this happens.

Ben

[Carl B. Johnson]

Ben

I have Ill 10, and will do as you said next time a file comes across my
desk. Thanks for your input.