How to Create 3D PDFs from FreeCAD Models

Creating interactive 3D PDF documents from FreeCAD models allows you to share rotatable, dynamic CAD designs with stakeholders who do not have specialized CAD software installed. While FreeCAD can natively export standard 2D drawing sheets to PDF, embedding an interactive 3D model requires exporting your geometry into a format recognized by the 3D PDF standard, such as Universal 3D (U3D) or PRC, and compiling it using external tools like MeshLab, LaTeX, or Adobe Acrobat Pro. This guide outlines the most reliable workflows to convert your FreeCAD parts into fully functional 3D PDFs.

Step 1: Export the 3D Geometry from FreeCAD

FreeCAD does not feature a direct, native one-click "Export to 3D PDF" button. You must first export your 3D model into an intermediate mesh or boundary representation format.

  1. Open your project in FreeCAD.
  2. Select the final body, part, or compound you want to export in the model tree.
  3. Navigate to File > Export.
  4. Choose an appropriate transfer format:
    • Wavefront OBJ (.obj) or STL Mesh (.stl): Best if you plan to convert the model via MeshLab.
    • STEP with colors (.step, .stp): Best if you are importing directly into professional authoring software like Adobe Acrobat Pro.
  5. Save the exported file to your computer.

Step 2: Convert to Universal 3D (U3D) Format

Adobe PDF requires models to be encapsulated in U3D or PRC formats to render interactively within standard PDF viewers. The open-source program MeshLab is the most common free utility for this conversion.

  1. Open MeshLab.
  2. Go to File > Import Mesh... and select the .obj or .stl file you exported from FreeCAD.
  3. Verify that the geometry imported properly and check that the surface normals are facing outward.
  4. Go to File > Export Mesh As....
  5. In the file type dropdown, select U3D File Format (.u3d).
  6. Save the file. Ensure the option to save vertex colors/materials is checked if your model relies on them.

Step 3: Embed the 3D Model into a PDF

Once you have generated the .u3d file, choose one of the following methods to compile your final PDF document.

Method A: Using LaTeX (Free and Open Source)

Using LaTeX with the media9 package is the standard free method for generating 3D PDFs.

  1. Install a LaTeX distribution (such as TeX Live or MiKTeX).
  2. Place your .u3d file in the same directory as your .tex document.
  3. Use the following minimal LaTeX template:
\documentclass{article}
\usepackage{media9}
\usepackage{graphicx}

\begin{document}

\includemedia[
  width=0.8\linewidth,
  height=0.6\linewidth,
  activate=pageopen,
  3Dtoolbar,
  3Dmenu,
  3Dc2c=0 2 0,
  3Dviews=views.mat
]{}{your_model.u3d}

\end{document}
  1. Compile the document with pdflatex or lualatex. The resulting PDF will contain your 3D model inside an interactive viewport.

Method B: Using Adobe Acrobat Pro

If you have access to Adobe Acrobat Pro, you can insert the 3D model directly into any existing PDF page without writing code.

  1. Open Adobe Acrobat Pro and open or create a blank PDF document.
  2. Navigate to Tools > Rich Media.
  3. Click the Add 3D button and drag a rectangular box onto the page where you want the 3D viewer to appear.
  4. In the dialog that appears, browse to your .u3d or native .step file.
  5. Configure display properties (lighting scheme, background color, default render mode) and click OK.
  6. Save the PDF.

Viewing the 3D PDF

Web browsers generally do not support interactive 3D PDF rendering via their built-in PDF viewers. Recipients must open the generated PDF in a standalone viewer that supports the Adobe 3D standard, such as Adobe Acrobat Reader or Foxit Reader, and ensure that 3D content rendering is enabled in the application's preferences.