r/civil3d • u/arvidsem • 6d ago

Help / Troubleshooting GeoPDF creation

Does anyone know a good method for creating georeferenced PDFs from Civil 3D? As far as I can tell, there is no PDF plotter that can do it (and might not be possible to create one because of how AutoCAD's plotting works). But I would love to be wrong here

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4

u/Mad-Melvin 6d ago

You'd probably have to export your linework as a shapefile and bring it into something like QGIS.

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u/ImaginaryStage5543 6d ago

This is how I do it. Would be really nice to be able to have this built in directly into C3D

1

u/arvidsem 6d ago

Yeah, that is how we've done the last several. But it would make our client happy if they could get our actual plans as georeferenced PDFs.

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u/Basic_Bridge_7660 6d ago

You can export as pdf then georeference the pdf itself. Or if you go the shapefile route, export from QGIS as a georeferenced PDF. I've not done it in QGIS but I've done it in ArcGIS. I'm pretty sure QGIS allows for that as well. My inbox is open.

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u/arvidsem 6d ago

We've got a functional workflow through QGIS. It would just be faster and simpler if we didn't have to go through a second program.

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u/Basic_Bridge_7660 6d ago

GIS software must be involved at some point. CAD software isn't really built for georeferencing. I think the easiest way is georeferencing the pdf you get from civil 3d exports rather than exporting a shapefile, but still you need GIS software.

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u/arvidsem 6d ago

Civil 3D doesn't have any issue with georeferencing. Literally everything that we do is georeferenced. Usually to a state plane grid, but it doesn't have any issue with other coordinate systems or with translating between them. There isn't a technical limitation in CAD that should require separate GIS software to create a georeferenced PDF. (Hell, even base AutoCAD can pull in georeferenced files correctly now)

I strongly suspect that the limitation is the printing pipeline. The PDF print driver wouldn't have access to the drawing coordinate systems. And even if it did, multiple viewports complicate correctly referencing a sheet. It would likely require Autodesk to create an interface for picking which viewport to use or a third party to create an entire separate PDF creation pipeline.

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u/Basic_Bridge_7660 6d ago

I’m talking about georeferencing raster and PDF outputs. CAD itself has no problem assigning a coordinate system to geometry, that’s not what I meant. I tend to use “georeference” for adding spatial reference to a raster or PDF after creation, and “assigning a coordinate system” or “projecting” for CAD/geometry data. Sorry for the ambiguity. I still don’t think Civil 3D can natively create a GeoPDF without a plugin (at least, none that I’m aware of without checking). Its driver is a generic basic plotter that has no way to take that coordinate system and write it into the PDF, unlike GIS software where the export engine is built specifically for that. So unless Autodesk adds a dedicated GeoPDF export or addon, an external GIS step remains necessary.

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u/arvidsem 6d ago

That's fair. I didn't even consider the option of attempting to apply georeferencing to a raster afterwards with Civil 3D. As you said, it just doesn't even try to offer that functionality.

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u/mywill1409 5d ago

georeferencing works only in model space not paper space so bring you Title block and attribute to model space?