Modeling Decorative or Artistic Shapes in CAD

Sometimes you’ve got to model things in CAD that CAD was never really meant to model. After all, manufacturing covers a lot of ground, and you need to be in step with it if you’re going to get the work. If it were easy, everybody would be doing it.

Even so, not everybody gets to (or has to, depending on your point of view) do this kind of work every day. I’ve previously posted some decorative stuff I’ve done for furniture, household and lighting fixtures in the past, and since I was modeling this chair for other purposes, I thought it might be nice to show it here.

Depending on what you are using the model for, this level of work can take a lot of time or not, and there are some techniques you can apply that will save you time and energy.

Let me start with what you can’t do with this kind of modeling.

First, you can’t really hold on to any kind of history-based puritanism. This type of modeling is far beyond where history-based CAD was meant to go, and if you keep clinging dogmatically to history-based best practice rules, you’re going to give up before you start. So you have to relax the rules. This kind of work is usually the realm of subd modelers, which have as the only rule that the end geometry needs to be correct. Nothing else matters. You need to adjust to this mindset if you’re going to do decorative or artistic work like this in feature-based, history-based NURBS CAD.

Features get out of order, and depending on the purpose of the model, you may not even wind up with a single solid body. So if you’re a pedantic purist, this kind of work is not for you.

And now what you can do if you got past the last couple of paragraphs:

In this example, I used a lot of 3D sketches. I’m sure that annoys a lot of people, but rigidly clinging to the plane/sketch idea along with separate sketches for separate features really holds you back. You might have the extra tendency to get stuck in this rut if you haven’t used anything except SolidWorks for your whole career.

There was a fellow who used to post stuff on the SolidWorks forum (https://forum.solidworks.com/message/972460) who did a lot of highly stylized religious iconography in SolidWorks for jewelry, castings, rings, statuary, and various other things. This was mostly in relief, so some of the 3D aspect of it was tamed to some extent, but his stuff was pretty impressive nonetheless.

The chair part was created from 227 features, and had hundreds of surface bodies and dozens of solid bodies. The bodies were created by patterns, and could have been trimmed and merged and solidified, but for this work, that wasn’t really necessary. The main point was to demonstrate features that look like upholstry puckers and carved feathers and waving banners are possible.

The most exotic feature I used was a Freeform that was used to give a smooth duck foot surface a bit of organic wavy-ness.

The banners were made from a combination of 2d splines and 3d splines, but they could have been all made using either type.

The puckers in the uphostry on the back of the chair were made by trimming out an irregular shape, and then lofting from an offset circle.

Like these, most of the techniques are not very difficult, it just takes some imagination to apply simple techniques to create a more complex effect.

The buttons were all placed with 3d curve driven patterns. You can make surfaces look like they have thickness with the Ruled surface. And the swans were much easier than you’d think. 2 sketches for the body, and just a sketch point for the beak.

In a way it’s a lot of fun trying to come up with methods for creating this geometry without spending weeks on it, but it also involves some taxing failure repetitions. Several of these models are going to be used in an upcoming online book/course I’m working on. These should be fun and different for people to work through. I’ll also have some more traditional models, but I wanted to show some of the more outlandish things you can do with a little imagination.