Using Defeature in 2019 to Speed Up Assemblies

If you have been following the blog you may know that we are preparing to renovate our training room and have been using SOLIDWORKS to assist with the task! Last time, I used 2019’s new Large Design Review to add components and mate them in place with magnetic mates functionality. It worked well for me, but now I need to fully resolve my assembly. What are the things I can do to predict and prepare for any performance remissions in the software?

Let's Start with Performance Evaluation

Let’s suppose that I am in my fully resolved assembly and I experience some stuttering when I rotate my model. Now what? First thing I do is open up the Performance Evaluation Tool which is found in the Evaluate Tab in assemblies. The dialog contains diagnostic information about my assembly, which is good, but what exactly am I looking for? The nice thing about the tool is that it points out performance outliers in all aspects. Consider the problem at hand:  stuttering when rotating. When you rotate, the model does not need to rebuild, so we can ignore Rebuild Time. Since the model is fully loaded, we can ignore Open Time as well. Something that does stand out to me though, is the Graphics Triangles count for all the components. Have a look:

We can see two outliers immediately: DESK72 and DESK30. They are two variations of the same desk, so both are practically the same component. By a huge margin, these components dwarf all other components in number of graphics triangles. So ,why do these components have a large triangle count? Let’s get them open and have a look.

At first glance, nothing seems out of the ordinary, but zoom in to any corner and the issue is apparent…there is a lot of detail orientation here. This desk has been modeled with near perfect characteristics. All the screws have actual geometric threads (which takes a bunch of triangles to represent) and there is a representation of every end cap and every decorative piece of plastic.

Let’s suppose that this level of detail is necessary (maybe we need to fabricate a copy of this desk in its entirety and need a cut list). Are we out of options? Well, turns out there is a way to get both an exact copy and a simplified version of this desk without having to do a lot of work.

Let's Check Out the 2019 Enhanced Defeature Tool!

As the name implies, the Defeature Tool takes a component and greatly simplifies it. It’s extremely beneficial, not only in performance increases but also in protecting intellectual property (i.e. remove all internal mechanisms). To use it, I’ll go back to the assembly and isolate one of the desks by right clicking the desk in the Design Tree > Isolate. This makes it easier to see what’s going on. Next, I’ll go to Tools > Defeature to launch the tool.

When the tool launches the option to choose the defeature method appears. The method that was added to 2019 is the second option Silhouette. It offers a whole new way to simplify components versus just suppressing features.

Once that is selected, hit the Next arrow on the top right.

Now, all we have to do is select bodies and choose how we want to simplify them. The simplification method depends on the overall shape of the model and how much detail we want to remove. There are so many options…

  • Have a body that needs to come out unchanged? Choose None (Copy Geometry).
  • Have a tube? Cylinder is probably your best bet.
  • Prismatic shape with a couple of bosses? Tight Fit Outline sounds ideal.

Play around with your options! If you don’t like how something simplified, you can delete the group (by right clicking > Delete in groups) and try another method. Below, you can see some of the choices I made with the model:

To select bodies, click into the box that has the icon with a blue cube next to a sheet of paper. Seriously, that’s what it looks like (it is also shown highlighted in the image above) and start picking bodies. Pick all the bodies that correspond to one simplification method and then hit Add Group. This will allow you to move on to the next selection set. Once you make the first group, the screen splits and shows you the preview of the geometry. After you’re satisfied, you can choose to save it as a new part if you wish. This is what the desk looks like now:

We can perform a File > Replace Components on all the files involved to improve the assembly.

From this preview, its almost impossible to see that these parts have desks that have been defeatured.

However, by looking at the performance, we can see how much lighter the assembly is. (NOTE: I left the part as the default defeature name, so the file name of the desk is FULL_CLARK_TRAINING_ROOM72_defeature. It really rolls off the tongue, I know.)

End Result

The desks went from having 1.5 million triangles to 5600 triangles, a reduction of over 265 times. I cannot express how valuable this is when working with large assemblies. Hopefully, you have found this helpful and thank you for reading!

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