Solid Edge 2021 Adds SubD Modeling

Solid Edge 2021 was presented in a What’s New show yesterday. There was of course a lot of new stuff across a wide range of topics. Even their hour long presentation was highly condensed. If you want to look more into the general What’s New, here’s a link to the presentation.

And that’s all nice, but what I want to talk about here is the fact that Solid Edge has added SubD modeling to their Classic and Premium levels of the software. Subd modeling falls under the Convergent Modeling header for Siemens that brings together various methods and data types, working together within a single CAD tool.

You can create subds in both synchronous and ordered. I’m not really sure what an ordered subd model would mean, possibly it’s just a stop on the history tree, not sure.

The changes you can make in subd modeling are decidedly non-history based. This is the kind of thing I was talking about when I was hoping that synchronous modeling could be brought to complex surfacing (synchronous surfacing). It doesn’t keep track of the steps you use to make a shape, the only thing that matters is the end shape. This type of workflow has been available in NX for some time, if I am not mistaken.

During the presentation, it’s kind of suggested that any body can now do complex shape modeling. Well, that’s kinda true. There is definitely a technique and certainly some skill involved in subd modeling. It is different, and possibly less technical than complex history-based surface modeling. I consider myself pretty good with history-based surfaces, but definitely a noob when it comes to subd. However, equivalent end products (complex shapely models) can be created much faster in subd than in history-based surfacing.

I should point out that the real end product is a NURBS surfaced model in both cases. It’s just that the interface for subd is like manipulating points, edges and faces, and applying blend properties to make smooth or sharp transitions. History-based surfacing is much more literal, and painstaking, and highly process-based. Even with subd capabilities, there may be times when you choose to use history-based methods.

The workflow for this type of modeling is to make a primitive (box, cylinder, sphere, torus) which is represented in a cage of points and lines. You can manipulate this cage to change the shape of the primitive.

The relationship of the cage to the surface shape is analogous to the relationship of the control polygon to a spline. You manipulate the shape indirectly by moving the points.

If you’ve never used subd before, it will certainly take some getting used to. Don’t expect to be brilliant at it right away. There are tons of Youtube videos of people doing this kind of modeling, mostly for CGI characters and cool cars. If you’ve ever wondered where people get excellent car models to do renderings on the SW site, they were probably made using subd (which does take skill, but it’s far less work than history-based surface modeling). Building a classic car model in CAD is truly an achievement, while doing it in a subd modeler is more a matter of visualization.

You can set up symmetry such that when you make changes to one side, they also effect the other side. You create detail by subdividing the faces into smaller and smaller faces. It is difficult to make large sweeping changes to small faces, but easier on bigger faces, so with subd you generally work from the big features to the small details, just like you normally would.

Instead of Loft, Sweep, Bluesurf, etc. your toolbox is Scale, Blend, Split, Fill. And then just like Synchronous changes, you have Tip and Lift options. Also like Synchronous, your toolbox operates on the selection, which can be points, edges or faces of the cage. It’s a more intuitive system. In comparison, history-based surfacing is more like programming a robot.

Once the subd modeling is done, you can operate on the model just like you would in normal solid modeling. You can add thin walls, ribs, bosses, and all of your other solid features. The subd model is going to try to create a solid, but you can force it to give you a non-manifold surface body if that’s the way you want to work.

I don’t have a ton of experience with this yet, as it was just announced yesterday, but I can see that for a lot of the organic shapes that I tend to work with, this is going to be such a better way to go than plodding with sketches and surfaces and settings. Especially for edits. Edits will be SOOOO much simpler.

And its free for students and startups.

I’ve said for a long time that for machine design type work, synchronous technology is the way to go. Now for organic design, subd modeling is the way to go. Soon you’re going to be out of excuses. You really owe it to yourself to check out Solid Edge 2021 and its subd capabilities.