Converting from PDF to Editable DWG?

Hello,

In speaking with someone today about CAD work, we got onto the subject of PDF to .dwg conversion, with which I have no experience. I asked my Dad (he's been doing this for, oh, about as long as I've been alive). He wasn't familiar with a good way to do it either. So here's the situation: the CAD lady there has so far had to re-draw all PDFs to be able to get a usable .dwg file. We want to find a way to convert the PDFs to an editable .dwg (so scale can be set correctly, etc.).

A little bit of background: She is using AutoCAD2013 LT, to the best of my knowledge. She creates "shells" for equipment floor plans for usually one room in a multi-room facility. So she receives a drawing from the facility and cuts out all the unnecessary rooms, etc. She then provides the floor plan of the one room needed to the person that will be laying out equipment within the room. A fair amount of the drawings she's been receiving have been PDFs as the facility doesn't have the original .dwg file.

In doing a little bit of research, so far I've found a few different programs. I've seen some good reviews of DotSoft. And I've also found information stating that AutoCAD LT 2017 has capabilities to convert PDF to .dwg. My questions:

Does anyone here have any recommendations of a good way to convert PDF to .dwg?

Any experience with DotSoft or 2017's capabilities?

I would assume that either of these would have issues with a scanned PDF, for instance, but would work OK if it was a drawing saved as a PDF. Is that the case or are scans sometimes acceptable as well?

On a different side note, in researching now it appears that one can no longer purchase, say, 2017. It looks like it can only be purchased for a year, then the license has to be renewed for next year. Is that the case? Is there any workaround? Is anyone getting any other deal for being a long-term user?

Thanks so much in advance for any assistance!

Lydia

AutoCAD 2018 has not been released yet so I see no reason why you cannot purchase AutoCAD 2017. There are no more perpetual licenses meaning you have to accept going to subscription and paying a yearly maintenance fee. The other alternative is to rent/lease AutoCAD. Further details can be obtained at the AutoDesk website.

How objects are handled during a PDF to DWG conversion in AutoCAD 2017....

Personally, I'd rather redraw from scratch.

There are actually some pretty good converters, the output usually depends on the quality of the PDF, etc.

If these are scanned raster PDFs, the best bet is to trace them. If they are not of the very best quality, the results are usually unusable in my experience.

If there is enough information on the PDF I usually just redraw from scratch, I don't even bother tracing.

Thanks for the help, ReMark and SLW210! Regarding purchasing 2017, you answered my question about perpetual licenses - that was what I meant when I said "purchase". I just wasn't using the correct terminology.

Thanks for the handy reference of what converts to what. Could you perhaps let me know where you found it so I could copy/paste it?

I would tend to think redraw as well, and that's what they've been doing. But she receives a large volume of drawings and has to crank them out pretty quickly. Apparently recently she's been getting a lot of PDF drawings so they're hoping there's a faster way.

When you say tracing, do you mean that usually the PDF is inserted into the drawing and you effectively trace what's there as opposed to the lines on the PDF being converted to lines in CAD?

The reference came straight from the AutoCAD 2017 Help file.

Users can insert a PDF using the ATTACHPDF command and trace over the image or if they have a digitizing board they can trace over a printed copy of the PDF. I've done both.

The full version of AutoCAD 2017 has built-in PDF to DWG conversion (vector only, not raster/scanned) and I have used it on numerous occasions and it works good. Granted, it's never perfect, but for background purposes, it is sufficient.

Before AutoCAD 2017 I used the free vector program Inkscape to import vector PDF's, then save as a DXF and it has worked well through the years. It's a bit of a process since you are using a second program. You have to import/save as, then open in AutoCAD and scale using a reference, and so forth. But, it works, and it's legitimately free (if cost is of concern).

-TZ

ReMark: That's what I was guessing, thanks.

Sorry for what may seem like a redundant question. I'm feeling a little dense here but just want to make sure I'm understanding correctly. No digitizing board, so it will be the former of the two options. When you say trace over, could you explain that a bit more? Is it literally "tracing over" with your mouse as you redraw lines over the lines that are currently there? I'm sorry, it's something I've never done. I've got 2013 educational on my computer and I don't want to lose that by downloading the 30 day trial of 2017. I'm not planning to purchase a license for this computer at this time since I don't use it for business.

TZ: Very impressive grill, by the way. I was looking at the thread for it last night. Very well done. I always love to see people working together to create a really nice, better than professional-quality piece of work, whatever it may be.

Thanks for the help! I'm glad to hear it works decently. What are the main things that are usually off? If it's scaled correctly, is it likely to have actual lengths be incorrect on one side of the drawing or is it generally less important issues? Like you said it is mainly background work for equipment layouts but I do think they're still going to want accurate lengths. I don't think they'd mind re-dimensioning it so if the bones are good that would be the main thing.

I'll give Inkscape a try with my 2013, thanks for the suggestion!

One other question, I see the terms vector and raster thrown around but quite frankly I'm not sure I understand them. Is vector effectively a drawing file that was saved as a PDF and raster a physical drawing that was scanned? Or something completely different? How would one tell off-hand whether a PDF is vector or raster?

Yes, it is literally tracing over on screen using lines or polylines. I usually attach the PDF to layer "0" then create and use a second layer (color: magenta or red for contrast) for the "tracing".

Raster (bitmap) vs. Vector

http://vector-conversions.com/vectorizing/raster_vs_vector.html

I'll reply to myself here a little. I just read more about vector vs raster and it appears raster is pixels and vector refers to the points, which are then filled in by lines or solids the computer. So vector will be smoother and better looking when resized, whereas raster will look pixelated. In this case, vector sounds much preferable. The question still remains, how are the vector vs raster images created? If the drawing was made in CAD and saved as PDF will that be vector? And how does one tell the difference?

ReMark: Thank you for explaining that. I definitely see why you say to just redraw if the necessary information is there. Sounds like it would be more trouble than it's worth for something like a floor plan.

Is there then no way to convert a PDF drawing to a .dwg/.dxf with editable lines, etc? Or is that what Inkscape does?

The PDF to DWG conversion process will give you editable lines it's just that some conversion programs produce better results than others.

Can you provide us with a sample PDF of a floor plan?

From VisualIntegrity....

TZ: Very impressive grill, by the way. I was looking at the thread for it last night. Very well done. I always love to see people working together to create a really nice, better than professional-quality piece of work, whatever it may be.

Thanks for the help! I'm glad to hear it works decently. What are the main things that are usually off? If it's scaled correctly, is it likely to have actual lengths be incorrect on one side of the drawing or is it generally less important issues? Like you said it is mainly background work for equipment layouts but I do think they're still going to want accurate lengths. I don't think they'd mind re-dimensioning it so if the bones are good that would be the main thing.

• Circles and arcs become segmented lines/plines.
  
• SHX fonts become lines instead of retaining their original TEXT entity so no editable text unless it was used with TTF fonts.
  
• Accuracy is compromised. Something that is exactly 36" long will become 36.125" or 35.95", for example.
  
• Unless Layers were retained during the PDF output process, no layers whatsoever.
  
• Hatches are completely exploded.
  
• Dimensions are exploded. In fact, most if not all things come in as an exploded state.
  

There are many others but these are the main issues.

-TZ

ReMark: I was typing a reply to a previous reply when the notification email came through. I read your response on the email but somehow I missed the link with information about raster vs vector. Excellent information, thanks for the link! Bookmarked for future reference.

Ok, that makes sense. So it might be worthwhile to try a few different programs if the first one doesn't work.

I'll see if I can get a sample PDF here shortly.

Thanks again for all the help!

Thanks! It's about time to fire it up.

 

The main downfalls are this:

 

• Circles and arcs become segmented lines/plines.
  
• SHX fonts become lines instead of retaining their original TEXT entity so no editable text unless it was used with TTF fonts.
  
• Accuracy is compromised. Something that is exactly 36" long will become 36.125" or 35.95", for example.
  
• Unless Layers were retained during the PDF output process, no layers whatsoever.
  
• Hatches are completely exploded.
  
• Dimensions are exploded. In fact, most if not all things come in as an exploded state.
  

 

 

There are many others but these are the main issues.

 

-TZ

Thanks for the list, that's very helpful. Just what I was needing to know. Ironically accuracy probably won't be critical as the customer likely won't be viewing the equipment layout in any type of software that they could even see the actual line lengths on. But since dimensions are exploded, it sounds like it would be necessary to re-dimension to have a truly useful drawing in which case the inaccurate line lengths are a problem again. So this comes back to just like you guys said, re-draw if it's not just being used as a background. Thanks so much for the good explanation.

I'll still try to get a sample PDF up here and will play around with it a little myself as well.

Thanks for the list, that's very helpful. Just what I was needing to know. Ironically accuracy probably won't be critical as the customer likely won't be viewing the equipment layout in any type of software that they could even see the actual line lengths on. But since dimensions are exploded, it sounds like it would be necessary to re-dimension to have a truly useful drawing in which case the inaccurate line lengths are a problem again. So this comes back to just like you guys said, re-draw if it's not just being used as a background. Thanks so much for the good explanation.

 

I'll still try to get a sample PDF up here and will play around with it a little myself as well.

I guess I should specify, it's not that I didn't believe you all when you said it's generally better to re-draw, I just wanted to know the "whys". Thanks again.

In full agreement with Tanner. ACAD 2017's PDF converter is pretty good. I use it as well and it does just as good as the other options out there but now included in AutoCAD.

The full version of AutoCAD 2017 has built-in PDF to DWG conversion (vector only, not raster/scanned) and I have used it on numerous occasions and it works good. Granted, it's never perfect, but for background purposes, it is sufficient.

 

Before AutoCAD 2017 I used the free vector program Inkscape to import vector PDF's, then save as a DXF and it has worked well through the years. It's a bit of a process since you are using a second program. You have to import/save as, then open in AutoCAD and scale using a reference, and so forth. But, it works, and it's legitimately free (if cost is of concern).

 

-TZ

Realized I never updated this. I looked on my computer thinking I would have some samples I could use but I don't have anything that's not an actual customer file, which I am not going to post to the internet. I'll give Inkscape a try at some point with some of the customer files I have and see how it acts.

Thanks again for all of your help!

One of the best PDF to vector drawing convertors I ever used was called PDFFLY.

Here's a quick review I did back in 2009 (I see I was a bit amused at the idea of Autocad ever incorporating it's own converter, how times change).

http://www.cadeverything.com/help/showthread.php/5277-PDF-to-DXF-conversion?

Of course things have moved on since then and the company now has a range of PDF conversion products for CAD.

Some are stand alone, some are plugins for Autodesk products, one is even a portable on a USB stick for where you can't install software on a works PC or if you are at a clients office.

http://visual-integrity.com/

They are not free, but trial versions are available.

If you find yourself frequently doing conversions then the time saved over redrawing from scratch will soon justify the cost.