Just as Adobe strove to make its PDF file format the industry standard for sharing documents and forms, so now is the company aggressively trying to make PDF the standard for CAD and 3D file-sharing. Starting with the first release of Adobe Acrobat 3D in early 2006, that prospect is moving closer to being fulfilled with better format support and capabilities enhancements in the latest revision of the software, Acrobat 3D version 8.
The first version (Acrobat 3D 7) was based on an open 3D format called U3D from the 3D Industry Forum. To capture 3D data, Acrobat would use a 3D screen capture function to digitally grab open graphics library data (a 3D standard), load U3D files, or automatically convert some formats via drag and drop. But U3D wasn’t particularly accurate and would often lose precise building information (such as tolerances and geometric dimensions) in translation.
Acrobat 3D 8 takes 3D PDF to a new level by improving compatibility and sprucing up the program with a new interface. By acquiring 3D conversion company TTF, Adobe was able to build powerful CAD translators into a new, highly compressed yet accurate format. The result is support for bigger, smarter two- and three-dimensional models that take up less space on your hard drive. Building Teams can share model data by being able to view PDFs in both Acrobat 8 and the latest version of the free Adobe Reader. U3D remains one of the formats embedded within the PDF, but with the addition of TTF’s PRC format, Acrobat 3D becomes much more powerful.
"What we heard a lot from AEC users was, ‘We love PDF and we love to share drawings, we just need the files to be even smaller,’" said Patrick Aragon, Acrobat’s senior product marketing manager. "Some of these new 3D PDFs are 50 times smaller than their native files."
In addition to supporting many CAD formats, Acrobat 3D also comes with an expanded list of compatible BIM formats. Autodesk DWG and DWF files and sheet sets are readable. Several BIM applications are able to be directly converted to 3D PDFs. Solidworks files can be directly converted. All Bentley applications can automatically be converted (Bentley was one of the few companies that supported U3D). Graphisoft’s ArchiCAD is already directly convertible to 3D PDF.
Although Autodesk’s Revit and Google’s Sketchup BIM programs can’t be converted directly to 3D PDFs, models created in them only require one screen capture and are readily translated thanks to the improvements from TTF. Object and building information data are retained with the new translators.
When enabled by Acrobat 3D, Building Team members, consultants, and clients can then use the latest version of the free Adobe Reader application (version 8.1) to review and add comments directly onto the 3D content embedded within the 3D PDF, without the need to have the original authoring application or any other CAD viewer. This could allow full building specifications to be sent out with information requests. Design firms could use 3D material (models or animations) for training manuals and presentations, and CAD files could be repurposed to a neutral PDF format for downstream building processes. The enhancements are a quantum leap beyond the conversion and translations in Acrobat 3D 7.
By simply pressing the "print screen" key in a 3D program such as SketchUp Acrobat 3D 8 generates a new 3D PDF file.
"One of the things AEC users wanted was the ability to use 3D or CAD content to increase efficiency of building projects," Aragon said. "That’s what the improvements are designed to do, increase collaboration on 3D designs early in the process and then allow them to take advantage of the robustness of the 3D format to repurpose and use that content
The resulting PDF file keeps all geometry and building information from the original SketchUp file.