How to Consume the PMI in a 3D PDF
In a previous article, “Getting Started with 3D PDF,” we looked into the 3D data communication barrier and how 3D PDFs can help lower this barrier. Then we shared several reminders on accessing a 3D PDF file.
Once a 3D PDF is opened and the 3D content is activated, we are presented with a wealth of information such as product and manufacturing information (PMI), texts, images, 3D viewports, predefined views, tree nodes and attachments. How can we take full advantage of this rich content? Let’s look into the PMI first in this article.
3D dimensions and tolerances attached to models are an important step in model-based definition (MBD). They convey critical engineering and manufacturing requirements, so it’s vital for downstream consumers to understand and act upon them correctly. One common problem, though, is how to relate a 3D callout to its associated features. A leader line pointing to a feature can help, but it doesn’t point to a group of features such as a pattern of multiple instances. And a leader line may sometimes be obscured by the model body. To illustrate the relationship between 3D callouts and their corresponding features, the ASME Y14.41-2012 standard requires the “visual response” capabilities. That is, when you click on a 3D callout, not only should the callout be highlighted, but also should the corresponding features it defines. SOLIDWORKS MBD supports this cross-highlighting behavior as shown in a previous post, “Top SOLIDWORKS MBD Tips and Tricks: Hole Callouts.” One step further, the 3D PDF published by the software also complies with this requirement as shown in Figure 1. This model can be downloaded at the National Institute of Standards and Technology (NIST) website. Please note that cross-highlighting only works in one way—from 3D callouts to features—not the other way around. The reason is that a feature, especially a datum feature, could be heavily referenced and lead to too many remotely associated 3D callouts. The highlighting is to let a few items stand out from the rest, but if too many items were highlighted all together, it would defeat the purpose of this differentiation.
Figure 1. Selecting one callout highlights all the countersink hole pattern instances in red in a 3D PDF.
The cross-highlighting behavior works on mobile devices too as shown in Figure 2.
Figure 2. 3D PMI cross-highlighting in green on an iPad.
Another common problem with viewing 3D geometric dimensions and tolerances (GD&T) is to envision the datum features. We need to know where datum features A, B, C or D, E and F are in order to make sense of a feature control frame. However, these datum symbols may not be visible or easily legible from the current perspective. So oftentimes, we have to search through multiple views, and rotate and zoom the model to locate these datum symbols. Then we need to remember what they point to as datum features. Finally, we must establish the reference frames to interpret a geometric tolerance. This issue is further compounded by multiple datum reference frames in complex models. To solve this problem, the 3D PDF by SOLIDWORKS MBD provides a context command, “Highlight associated datums,” when you right-click on a feature control frame as shown in Figure 3.
Figure 3. Highlight associated datum features in a 3D PDF.
Now three datum features are highlighted in red, along with the positional tolerance control frame callout and its associated hole pattern on the base plate, as shown in Figure 4.
Figure 4. Three datum features (the bottom face, a bigger mounting hole on the left and a smaller hole on the right) are highlighted automatically.
You may have noticed another context menu command, “Highlight associated PMIs,” in Figure 3. This command highlights the corresponding hole diameters and the constructive basic dimensions for this positional tolerance as shown in Figure 5.
Figure 5. Highlight associated PMIs in a 3D PDF.
These cross-highlighting behaviors can help retrieve key information quickly, confirm the desired features and speed up the comprehension of and executions according to the 3D dimensions and tolerances.
Besides 3D dimensions and tolerances, tables are also often used to organize scattered bits and pieces of information. Bill of materials (BOM) is one of the most frequently used cases. Figure 6 shows the bidirectional cross-highlighting between a 3D viewport and a BOM table. You can click on a component in the viewport, and then the corresponding line item in the BOM table will be highlighted such as the line item number 10, tubing top section, shown in Figure 6.
An engineer once asked me what would happen if a line item was not displayed yet in a long BOM list. The answer is that you don’t have to manually scroll up or down the list to locate it. Your click on a viewport component will automatically find its line, scroll the list to make it visible and then highlight it.
Please notice that the cross-highlighting here is bidirectional. Clicking on an item in a BOM table will also highlight the corresponding components in the viewport. This can help you to locate a component in the way you prefer, either from a viewport or from a BOM table.
Figure 6. Bidirectional cross-highlighting between a BOM table and a 3D viewport.
A SOLIDWORKS MBD 3D PDF can also be published with generic tables saved from the software. Figure 7 shows a simple title block in a published 3D PDF. And Figure 8 shows the insert generic table command inside the 3D PDF template editor. Once a generic table is defined onto a 3D PDF template, the linked custom properties in the table will be automatically populated with the actual model values during the publishing step.
Figure 7. A title block published per an inserted generic table (top).
Figure 7. An inserted generic table in the 3D PDF template editor.
The article, “How to publish a 3D PDF with SOLIDWORKS MBD,” explains more details about the publishing steps. Another blog post, “How to Use 3D PDFs,” will walk you through the basic tools available in Adobe Reader. Last but not least, you may also download several 3D PDF samples published by SOLIDWORKS MBD at a forum post. I’d love to hear your feedback on publishing and consuming 3D PDF in the comment area below. To learn more about how the software 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.