Large assembly performance can be greatly improved by removing features or geometry that increase rebuild time and require massive amounts of graphics triangles. Sometimes there are design details that must also be removed if we need to share our design outside of your organization. SOLIDWORKS includes two excellent tools to do this, but they are distinct and can be applied differently: the simplify utility and defeature tool.
What does simplify do?
Simplify determines an “insignificant volume”, based on a user defined simplification factor of feature volume against the entire part/assembly, and creates a derived configuration that suppresses features within that insignificant volume.
There are two methods of simplification beneath this that SOLIDWORKS can perform: feature parameter and volume based. Feature parameter will simplify those features with parameter values beneath the insignificant volume factor, and volume based will simplify features based on their volume within parts and assemblies. Speaking of assemblies: if a feature is critical to your mate structure but is beneath the volume, you can choose to ignore features affecting assembly mates.
Running this utility will calculate the insignificant volume and then suppress those features to give you your simplified model.
When should I use it?
If improving performance is fishing, simplify is a bit like casting a net. Although it may lack some precision in what we catch, it’s great for catching a lot at once. You can always cross reference with performance evaluation as well to better understand the bottleneck in your rebuild time, and target those features individually. The simplify SOLIDWORKS tool will improve not just graphics performance, but rebuild performance too by suppressing features. If you’re looking for the best option for overall performance benefits at the part and assembly level, this is a great option.
What does defeature do?
Much like simplify, defeature removes details from assemblies and parts, but it does this in a different way with different end results. Using defeature for parts allows you to utilize the simplify geometry method to remove or keep bodies and features. The part must then be saved out as a new document, or published to your supplier services account on 3D Content Central. At the assembly level, the defeature tool becomes more powerful by not only being able to do what it can do at the part level, but you can also utilize the silhouette method. This method will allow you to specify groups to defeature, and will abstract the geometry of the group according to the silhouette method selected. It can be saved into a new part, or as a derived configuration.
When should I use the defeature tool?
Defeature is good for reducing features to send out parts externally so that proprietary information is hidden and parts are non-editable. Since the end result is new documents most of the time, rather than a derived configuration, it may not make sense for your workflow. That new document is also a dumb solid, meaning there is no feature history to go through. I think one use case though where it will outshine simplify is if you have an imported subassembly that is demanding graphically due to many graphics triangles. Since we don’t have a feature history to simplify, we can use the silhouette tool to reduce the number of faces and therefore graphics triangles required on that component, since we may only need its representation in our model. We can always quickly toggle back and forth as well, since this will work as a derived configuration. Defeature via the silhouette method is a great method to improve performance at the assembly and subassembly level, but look to use simplify at the part level when you have a feature history.