3D PDF is a PDF document embedded with 3D content. It can be opened with the free Adobe Reader, which has been installed on 95 percent of Internet-connected computers. You can pan, zoom and rotate the 3D models, callouts and other content using Adobe Reader in a way similar to CAD products. It greatly lowers the 3D content consumption barrier for those who don’t have CAD products installed on their computers. Figure 1 shows a multiple-page 3D PDF example published by SOLIDWORKS MBD. You can download it from a previous blog post, “How to Use 3D PDFs.”
Figure 1. A multiple-page 3D PDF example published by SOLIDWORKS MBD.
Because of the rich and easy-to-use 3D content viewable in the ubiquitous Adobe Reader, 3D PDF has become an important contributing factor to model-based definition (MBD). However, adopting 3D PDF doesn’t necessarily mean a successful MBD implementation. On the flip side, a successful MBD implementation doesn’t necessarily need 3D PDF either.
Let me explain the first point first. 3D PDF is just one of the contributing factors to enabling MBD. There are many other factors to consider in an MBD implementation. A previous blog post summarized three key perspectives within an organization—people, process and product—along with detailed recommendations and lessons learned. As proven by many manufacturers rolling out MBD, the most challenging obstacle is not technology, let alone 3D PDF. It’s the team member’s 2D drawing mindset and the process shift. So please don’t underestimate the scope of an MBD implementation. It’s not as simple as adopting 3D PDF.
Furthermore, even at the technology level, 3D PDF itself has many variations, and we need to be discerning about what to adopt. 3D PDF started with a format called Universal 3D (U3D) in 2004. The last U3D format edition was published in 2007. In other words, it hasn’t been updated for nine years. Common issues with U3D include low data fidelity, poor quality of 3D model rendering, slow response speed and large file sizes.
A new 3D PDF format is called product representation compact (PRC), which was established as ISO 14739-1 standard in December 2014. As noted by the 3D PDF Consortium, the PRC format is an accurate, highly compressible 3D data format optimized to store, load and display various 3D data, metadata, assembly structure, graphics information and product manufacturing information (PMI). To improve the output quality and comply with the ISO standard, SOLIDWORKS upgraded the underlying 3D PDF technology from the U3D format to the PRC format in 2015. The example shown in Figure 1 is based on the PRC format.
A point worth mentioning is that you don’t need a SOLIDWORKS MBD license to publish a 3D PDF. Figure 2 shows a gear box assembly model with integrated PMI and 3D views in SOLIDWORKS.
Figure 2. A gear box assembly model with integrated PMI and 3D views in SOLIDWORKS.
You can save this assembly as a 3D PDF by checking the box in the orange circle as shown in Figure 3.
Figure 3. Save a model as a 3D PDF.
Figure 4 shows the saved result of a basic 3D PDF.
Figure 4. A basic 3D PDF saved in SOLIDWORKS.
As you can see, the PMI and 3D views are not saved into this document. It contains only one viewport and one sheet. Although it is based on the PRC format and is embedded with a 3D model, it falls short in meeting other important MBD needs as noted above. Therefore, the 3D PDF published by SOLIDWORKS MBD(as shown in Figure 1) is highly recommended for your MBD implementation. Table 1 summarizes the key differences between the 3D PDF documents saved in SOLIDWORKS and those published by SOLIDWORKS MBD.
Table 1. Differences between the 3D PDF documents saved in SOLIDWORKS and those published by SOLIDWORKS MBD.
| 3D PDF Output | SOLIDWORKS | SOLIDWORKS MBD |
| PMI | No | Yes |
| Custom Properties | No | Yes |
| Bill of Materials (BOM) | No | Yes |
| Customizable Templates | No | Yes |
| Multiple Configurations | No,active configuration only | Yes |
| Display States | No | Yes |
| Product Views (3D Views, Named Views, Predefined View Orientations) | No | Yes |
| Multiple Sheets | No | Yes |
| Multiple Viewports | No | Yes |
| Multiple Tables | No | Yes |
| Attach Multiple Files Upon Publishing | No | Yes |
| Automatically Attach STP242 Files | No | Yes |
| Accuracy and Compression Options | No, fullest compression only | Yes |
In summary, an MBD implementation requires much more than 3D PDF. Mindset and process shifts are far more challenging than technologies. Also the 3D PDF technologies involve multiple levels. The rich and production-quality 3D PDF based on the PRC format can serve you better.
Now let’s move on to the second point. A successful MBD implementation doesn’t necessarily need 3D PDF. As mentioned above, 3D PDF is great for team members who don’t have access to CAD products to consume the MBD data. However, for those who do use CAD products, the native CAD formats can best preserve the data intelligence and avoid the conversion errors. Let’s remember: Although the 3D PDF by SOLIDWORKS MBD can reach less than 1-micron accuracy from the native model, as a neutral format, it can’t and shouldn’t retain all the native information.
Because of the data fidelity considerations, Gulfstream, along with all the suppliers, is standardized and synchronized on one engineering software platform. “I can’t tell how big of a difference it has made to the [MBD] implementation,” said Dan Ganser, product lifecycle management staff scientist at Gulfstream.“Not having to convert data is unbelievable.”
Therefore, when you are evaluating MBD technologies, please start with your objectives. For instance, if you just need the visual presentation and accurate measurement of the 3D models, then the 3D PDF published by SOLIDWORKS MBD can satisfy this need. If you want to use the intelligent model and representational PMI to drive downstream manufacturing applications such as computer-aided manufacturing (CAM) and a coordinate measuring machine (CMM), then the native models work better. As of November 2016, I’m not yet aware of a CAM or CMM software application that can read the 3D PDF model integrated with PMI and program automatically. It may become possible in the future as the technology evolves.
Besides 3D PDF, there are also other approaches to share MBD data. For example, the STEP format is widely used at machine shops. In 2014, ISO published the first edition of STEP AP 242, which specified the PMI support for this neutral format. SOLIDWORKS MBD 2017 can publish STEP 242 with graphical PMI (see Figure 5), and eDrawings 2017 can read it (see Figure 6).
Figure 5. Publish STEP 242 with PMI using SOLIDWORKS MBD 2017.
Figure 6. Read STEP 242 with graphical PMI in eDrawings 2017.
In addition, as described in a previous blog post, sharing MBD data over the Web has become increasingly promising. Figure 7 shows an image of an interactive MBD model from an iPhone’s Web browser.
Figure 7. An interactive MBD model from an iPhone’s Web browser.
I hope this article can help clarify 3D PDF and MBD a bit further. 3D PDF is one of the contributing factors to enabling MBD, but it’s certainly not everything. Native CAD formats are the best for preserving the MBD intelligence. In addition to 3D PDF, STEP 242 and MBD data over the Web are also promising approaches for sharing and collaboration. To learn more about how SOLIDWORKS MBD can help you with your MBD implementations, please visit its product page.
About the Author
Oboe Wu is a SOLIDWORKS MBD product manager with 20 years of experience in engineering and software. He is an advocate of model-based enterprise and smart manufacturing.