progeCAD PDF to DWG Conversion: Import, Vectorize, and Clean Up Workflow

progeCAD PDF to DWG Conversion: Import, Vectorize, and Clean Up Workflow

progeCAD includes a built-in PDF-to-DWG converter that imports PDF vector data as editable DWG entities. Unlike AutoCAD's PDFIMPORT which requires a separate command, progeCAD's converter is integrated directly and handles vector geometry, text, and fills in one operation. This guide covers the complete workflow from PDF import to clean, editable DWG output.

Understanding PDF Content

A PDF can contain three data types:

1. Vector paths — lines, arcs, curves stored as mathematical paths. Convert cleanly to DWG.
2. Text characters — stored as Unicode with font references. Convert to TEXT/MTEXT if fonts are available.
3. Raster images — scanned drawings or screenshots. Cannot convert to vectors natively.

Before importing, verify the PDF source. PDFs generated from CAD applications (via plot or export) contain vector data. Scanned PDFs contain only raster images and require external OCR/tracing.

PDF Import Process

Command: PDFIMPORT

1. Type PDFIMPORT or use Insert > PDF Import
2. Select the PDF file
3. Choose the page (for multi-page PDFs)
4. Configure import options:

Import Options

• Vector geometry: Import lines, arcs, and polylines from PDF paths
• Solid fills: Import filled regions as solid hatch entities
• TrueType text: Import text as MTEXT entities
• Raster images: Import embedded images as image references
• Layers:
  • Create from PDF layers — preserve PDF layer structure
  • Use current layer — all entities on current layer
  • Separate by type — lines on one layer, text on another, etc.

Scale and Position

• Insertion point: 0,0 or click on screen
• Scale: 1:1 if PDF was plotted at 1:1; otherwise calculate scale factor
• Rotation: 0 for standard orientation

Post-Import Cleanup

After import, perform these cleanup steps:

Step 1: Join Fragmented Lines

PDF vector paths import as short line segments. To fix:

1. Select all lines on a layer
2. Use PEDIT > Multiple > Join
3. Set tolerance to 0.01mm to connect segments with small gaps
4. Repeat for each layer

Step 2: Fix Text Heights

PDF text may import at incorrect heights due to font substitution:

1. Select all text entities
2. Check actual height in Properties panel
3. Compare with expected height
4. Use SCALE with reference to correct all text

Step 3: Assign Layer Colors

PDF colors don't always map to standard CAD colors:

1. Open Layer Manager
2. Assign standard colors: 1=red, 2=yellow, 3=green, 4=cyan, 5=blue, 6=magenta, 7=white
3. Set linetypes per layer

Step 4: Remove Zero-Length Lines

PDF imports often contain extremely short line segments:

1. Use QSELECT — select all lines with length < 0.01mm
2. Delete them
3. Run OVERKILL to remove duplicates

Step 5: Verify Scale

1. Measure a known dimension (e.g., door width should be 900mm)
2. Calculate correction: actual / measured
3. Select all entities and SCALE by the correction factor

Handling Scanned PDFs

If the PDF is a scanned drawing (raster only), progeCAD's PDF import will bring it in as an image reference, not editable geometry. Options:

Option 1: Manual Tracing

1. Import PDF as image: IMAGEATTACH
2. Set image layer to light gray
3. Lock the image layer
4. Trace over geometry on new layers
5. Delete or freeze image layer when done

Option 2: External Raster-to-Vector

Use a dedicated tool (Scan2CAD, WinTopo, AutoTrace) to convert the scanned PDF to DXF, then import with DXFIN.

Batch PDF Import

For multiple PDF files, use a LISP script:

(defun c:BatchPDFImport ( / pdfdir pdffiles filename)
  (setq pdfdir (getstring "\nPDF folder path: "))
  (setq pdffiles (vl-directory-files pdfdir "*.pdf" 1))
  (setvar "FILEDIA" 0)
  (foreach filename pdffiles
    (command "_.-PDFIMPORT" (strcat pdfdir "\\" filename) "")
    (princ (strcat "\nImported: " filename))
  )
  (setvar "FILEDIA" 1)
  (princ "\nBatch import complete.")
  (princ)
)

Common Import Issues

Issue: Text Imports as Outlines

Cause: PDF was created with text "curves" option (text converted to vector outlines). Fix: Cannot convert back to text. Delete outlines and retype using TEXT or MTEXT.

Issue: Hatches Import as Individual Lines

Cause: PDF hatch patterns stored as line segments, not fill regions. Fix: Select lines in hatch area, use HATCH with "Select Objects" to create proper hatch, delete original lines.

Issue: Geometry Is Offset from Origin

Cause: PDF was plotted with non-zero origin offset. Fix: Select all entities, use MOVE with a base point at a known location to shift everything to 0,0.

Exporting Clean DWG

After cleanup, export for AutoCAD users:

1. Run PURGE to remove unused objects
2. Run AUDIT with Y to fix errors
3. Set DWGFORMAT to 2018
4. Use WBLOCK to write a clean file (strips custom data)
5. Verify in AutoCAD if possible

Batch PDF Conversion Workflow

For processing multiple PDF files, create a simple batch workflow: use progeCAD's scripting capabilities to automate the import and cleanup process. A typical batch script opens each PDF, runs the import with specified settings, executes a cleanup routine (OVERKILL to remove duplicate lines, JOIN to connect fragmented segments), and saves as DWG. The key settings to standardize are: import vector geometry only (skip raster), use the PDF page size as the drawing limits, and set the insertion scale based on the PDF's stated scale. For scanned drawings that come as image-only PDFs, you'll need a separate raster-to-vector tool — progeCAD's PDF import only handles vector data.

Identifying Vector vs Raster PDFs Before Import

Before attempting PDF-to-DWG conversion, it's critical to determine whether the PDF contains vector data or raster images. A vector PDF was typically created by exporting from a CAD program — the geometry is stored as mathematical paths and will convert cleanly to DWG entities. A raster PDF is usually a scanned drawing — the geometry is stored as pixels and cannot be converted to DWG without OCR and raster-to-vector processing. To identify which type you have, open the PDF in a viewer and zoom in to 400% or more. If lines remain sharp and clear at high zoom, it's vector. If lines become pixelated and blurry, it's raster. Another test: try selecting text in the PDF — if text is selectable, the PDF likely contains vector data. If text cannot be selected, it's probably a scanned image. progeCAD's PDF import will produce poor results with raster PDFs — you'll get a raster image embedded in the DWG rather than editable geometry. For raster PDFs, use a dedicated raster-to-vector tool like Scan2CAD or AutoTrace before importing.

Conclusion

progeCAD's built-in PDF-to-DWG converter is a practical tool for converting vector PDFs back to editable geometry. The key to success is understanding what the PDF contains (vector vs raster), using the right import options, and performing thorough post-import cleanup (join lines, fix text, assign colors, verify scale). For scanned PDFs, manual tracing or external raster-to-vector tools are needed — progeCAD's import only handles vector data. For batch processing, a scripted workflow with standardized import settings and automated cleanup routines can save significant time when converting large archives of PDF drawings. By following this workflow and setting realistic expectations about conversion quality, you can convert legacy PDF drawings back to editable DWG files efficiently without purchasing a separate PDF-to-DWG conversion tool.