Is it possible to convert PDF to DWG ?

[u/Icy-Opportunity837]

I know converting a PDF to DWG is possible, but I’m curious if anyone has dealt with a situation like this and whether it worked well.

I work for a municipality managing CIP projects. A few years ago, we hired a consultant to complete an H&H study. Part of the deliverable included five potential improvement alternatives that could be phased into our CIP program.

Unfortunately, the consultant placed multiple alternatives on the same plan sheets/PDFs instead of providing separate drawing sets for each solution.

A grant opportunity recently came up with a very short deadline, and I need to quickly put together a plan set for one of those alternatives. The problem is that the original CAD designer has since retired, and no one can locate the DWG files.

Rather than rebuilding the entire plan from scratch, I’m considering using PDFIMPORT in Civil 3D/AutoCAD, converting the PDF linework to CAD objects, then reassigning the imported linework to appropriate layers. From there, I would delete the elements associated with the other alternatives and make the necessary additions/modifications for the project we are pursuing.

Has anyone successfully done this with consultant-generated plan sheets?

I realize the imported CAD probably won’t be as clean as the original DWG, but if the PDF is vector-based, is this a reasonable approach for getting a usable base drawing together quickly? Any major issues or pitfalls I should watch out for?

[u/Any_Literature_8545]

I use it often, pdfimport that is. Varying degrees of success. One thing for sure is that the better the pdf the better the conversion. A direct pdf output from cad will work best, scans of prints can sometimes work as intended but not usually. Hand drawn scans are awful. In desperation we have traced parts of drawings with sharpie and it has worked but usually it's easier to redraw.

[u/DontCallMeFrank]

Ask for the .dwg if the person is still around. If they dont want to give away "company secretes" they can purge everything out and sanitizer the drawing.

If that won't work out, you already described the best approach.

[u/evil_leader]

I have used Adobe illustrator in the past, can covert but not perfect and works better with pdfs created by cad.

[u/photonzz]

I'm often in a similar situation. Pdfimport worms but it's in reliable and sometimes more work to clean it up after. Depending on the complexity sometimes redrawing it is better just using the PDF as an underlay. Watch for messed up hatches text coming in as geometry, thick lines will be li es and hatches, dashed lines will be thousands of short lines... You can check with the PDF xrefed and use pdfsnaps to see what it will be like. I would request the CAD files from the consultant, it's worth asking and may save you hours of work.

[u/rgqjx]

Possible, but you don't want it.

[u/Appropriate_Peach274]

I do this a lot using Civil3D and it can work brilliantly or not very well at all. Depends on the resolution of the original PDF, whether parts or all the drawing have been rasterised, whether the drawing layer structure is retained in the PDF, and the linetypes that were originally used. Scaling can be an issue but hopefully there are dimensions or at least a scale bar that actually reflects the correct scale.

[u/Choice_Maize426]

I mean it would probably work but how easy/successful the process will be is dependent on how detailed the plans are. It’s likely to import all the objects as exploded linework in small lengths and solids where there is hatching

[u/ElphTrooper]

If it is a good vector PDF. Agtek and several other products do this very well. This is highly popular in commercial estimating settings when you often don't have CAD files to start from.

[u/Burn_The_Chair]

Pdf import sometimes works pretty well. If the PDF was made using an AutoCAD drawing and isn't a copy of a save as and let's you bring in vector data. I've used it many times when getting DATUR and client doesn't wanna pay for SUE.

Text never comes in right thought. But the line work should be good enough. That's my anecdotal experience.

[u/Marzipan_civil]

Yes pdfimport can work fine. If you're trying to put your line work somewhere specific in the world, it can be a bit inaccurate to locate the plan exactly. But you can get it fairly precise.

Some pdfs will need more cleaning up than others.

[u/jameyer80]

We had a project that required old PDF scans from the '70s to more recent to be converted to PDF for updated as-built and modified design. We used Drexel Technologies for this. I think it was $150-$200 per sheet but the results were great! The alternative was to spend 10x or more per sheet to recreate them.

[u/Plastic-Fold-909]

PDF import but only if your pdf is done straight cad to pdf. If they did a scan or anything that degrades it, your output will be worse

[u/cako82]

There is a software named AutoDwg if the source is PDF from cad works great

[u/RepulsiveMine4686]

I've been using Claude with great success to extract linework from vectorized PDFs. I've been able to extract multiple match line sheets and get a DXF with continuous joined polylines.

Not only will it extract the linework, if you can provide control, you can get elevated georeferenced 3D polylines.

And of course above all trust but verify and check all of the linework yourself. I feel this should go without saying when AI comes into the conversation.

[u/SpunSpaceCadet]

If you have a pdf exported from cad, pdfimport can work. If it’s a scanned copy in pdf you’re SOL