U3D - How to embed navigable 3D models in PDF documents

[Greg Kmethy]

U3D (“Universal 3D”) is a file format for 3D data. It is a standardized three-dimensional data format with the purpose of facilitating 3D data exchange among programs of various kinds. Adobe Acrobat supports this format from version 7.0, so within a PDF documents 3D models can be represented, not only as static images but as real 3D objects. You can navigate through the model, set view options and save preset views.

To create such document with ARCHICAD and Adobe Acrobat:

• Open your project in ARCHICAD and go to a 3D view, in save as dialog you have the option to save a .U3D file
• In an U3D compatible PDF editor - like Adobe Acrobat 7.0+ you have the possibility to add U3D files as objects. For example in Acrobat 7.0:
  1. Open the PDF you would enhance with a 3D model
  2. Choose Tools/Advanced Editing/3D Tool
  3. Define the place of the 3D object on the paper
  4. Choose the .U3D file in the upcoming dialog and follow the instructions
  5. Click OK to place the model
  6. You can create here preset views for each placed U3D views - or later by opening the PDF
  7. After you saved the .PDF you can check the result in any U3D compatible PDF readers - like in Adobe Reader (note that Preview on Mac does not support U3D, but Adobe Reader also exists on Mac as a free product)
  8. Click on the model to activate the 3D navigation

To create such document within ARCHICAD:

1. Open your project in ARCHICAD and go to the 3D window.
2. Save a View in the View Map.
3. In the “save as” dialog, set the file format to a .U3D file and export the view.
4. Go to the Layout.
5. Place the View from the View Map onto a Layout.
6. Add this Layout to a Publisher set and set the file format to PDF.
7. Go to Document Options, and click PDF Options.
8. Check “Embed 3D Content”.
9. Browse for the exported .U3D file.
10. Select the View in the drop down list.
11. Publish the PDF

Here you can see a simple example how it works with a simple model:

Download the file: U3D.pdf Save it to your hard drive and open it for example with Adobe Reader.

Some recommendations:

• Keep the polygon number as low as possible, because large models can be slow in Adobe Reader
• Based on a couple of tests an U3D file works smoothly on an average computer till the file size of 10 Mb (not the .pln size)
• Larger models also work, but to activate the 3D view can take a couple of minutes
• Use the marquee tool to select only the part of the model you would like to share (right click on an empty place - show Selection/Marquee in 3D)