Chad Jackson

What is NXSketch?

June 18, 2020

What exactly is NXSketch and why do we need more sketching tools or big sketching enhancements? The latest version of NX was announced in June. They have a whole bunch of enhancements to NX, but one particular point of emphasis is improving how you are able to create and modify sketches. They’re calling it NXSketch.

What is NXSketch?

What exactly is NXSketch and why do we need more sketching tools or big sketching enhancements? So here’s the background. The latest version of NX was announced in June. They have a whole bunch of enhancements to NX, but one particular point of emphasis is improving how you are able to create and modify sketches. They’re calling it NXSketch.

It’s actually kind of a big deal. You spend a lot of time sketching profiles that you then might extrude or sweep or revolve to create 3D models for mechanical design for mechanical hardware. Engineers spend a lot of time creating these sketches. There are some unusual challenges that come with that. But before we get into those challenges, let’s talk about how it works.

How Does NXSketch Work?

If you think about this new capability for sketching, it actually has a parallel with parametric modeling. By using this approach, you can build up a 3D model using features. You have all these dimensions that you can use to control and modify that 3D geometry. There’s a lot of relationships between the features that are used to build that model.

The equivalent of that is this sketching approach that’s been used in the industry for a long time called constraint-based sketching. And what it does is, for the sketch that you create, every single piece of geometry or 2D entities that you put in there, they are dimensionally controlled and constraint controlled. So you know something is horizontal or vertical or parallel to something else or concentric, those are constraints. And then you also have all these dimensions that control it. So everything is explicitly defined. You know where everything is located. And that’s the way things have worked so far.

Let’s pause there for a moment and talk about this traditional constraint-based sketching approach. It’s worked great for years. People have used this constraint-based sketch approach for everything. It’s the way you extrude things and revolve things. Basically, it’s the way you build 3D models and that’s worked well.

The challenge is when you have a situation where you have very large, complex sketches. It gets bogged down when you try solving those constraints and dimensions interactively in real time. For example, if you have 100 or 1,000 entities in your sketch. It’s a ridiculously large assembly, right? And there’s always improvements that you’re trying to make there. But it can really get bogged down with performance there.

The second kind of scenario where there’s an issue is with imported drawings. You bring in a drawing. You want to make a modification and it’s got thousands of entities. Each of those things is a 2D independent thing that can be modified. If you try and go through and constrain and dimension all of that, the application can get lost. Literally, it can go away and become non-responsive and that can become a major issue.

These issues have been around for a while. There’s been some recent inspiration to deal with this issue. It goes back to 3D modeling. We talked about parametric modeling and we talked about constraint-based sketching. So the parallel here is actually direct modeling. You can bring in incredibly large, incredibly complex 3D models that you then can modify. The trick is when you select a piece of geometry, direct modeling, almost in any solution will assess the related geometry that needs to move it with this thing. If you select a surface, what’s the related geometry that needs to move along with it? And it kind of does that through inference, which is really cool. This means you can make small changes to a localized piece of geometry and do that quickly, easily and without having to work with the feature list at all. As a matter of fact, you can do it with imported geometry with no issue whatsoever.

And that’s kind of the concept that’s being applied here. You can select a 2D entity to modify. It will use inference to figure out the other 2D entities that are related or attached to this thing. And when you drag it, the other 2D entities will change, too, in a very smart, very intelligent way. We call this approach direct sketching because of the parallel to direct modeling. And it has huge implications for the issues that we talked about before.

Those implications are that you have higher performance because you’re not assessing the entire sketch. It’s very responsive. You can make changes to imported sketches or 2D drawings, layouts for machinery and stuff like that, that have a lot of 2D entities, too. And it reacts intelligently, but it’s not constraining every single thing. You’re not solving the entire sketch all at once. You’re only doing it to this local little area. It smartly and intelligently figures out what else needs to change with it.

This capability can provide a huge productivity boost, both with existing designs, new designs, drawings, and machine layout. Those are some of the applications that the folks at Siemens have talked about already where this can be used. So that’s why this NXSketch capability is actually kind of groundbreaking. It offers some capabilities that I haven’t really seen anywhere else, and it can be very, very powerful.

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