Try using the new Patch command in Rhino WIP; it has already replaced XNurbs. As an XNurbs user, I’ve made several comparisons, and it’s already a valid substitute.
Here is an example of a project where I’m using it. (patch vs xnurbs)
For what concerns the various modifications, it’s only partly true that parametric modeling takes less time — or rather, it’s true only in certain situations. To simplify, mainly when dealing with “standard” geometries like boxes or simple surfaces. I can assure you that when you work with complex surfaces, parametric modeling is not that useful.
I generally work with complex geometries, often including patterns and textures. Everyone I see working with parametric tools eventually gets frustrated, because the software is not as “intelligent” as it’s advertised.
For example, in my case I work in the footwear industry. I see colleagues and companies who, when dealing with simple heels, wedges, or basic soles, use parametric tools and say: “Yes, but I can do this in 5 or 15 minutes, while you might take half an hour.” That’s true — as long as you stay within simple geometries. But once you move to complex shapes, the situation changes completely, and I become much faster.
It also depends on how you set up your workflow. I always structure my work so that any modification can be done quickly, because I expect client revisions.
Take for example a wedge created in size n° 37. When I need to develop it across sizes 34 to 42, the geometry underneath never truly matches, because soles are handmade and not as precise as people claim. So I need to adjust the contact areas, and the parting planes change as well. However, I must keep the same base: everything scales except the base, and also the upper area where the heel or wedge sits (the “crown”). The side-view inclination must maintain the same angle, but in X and Y it must scale. In the lower part of the heel, certain areas must remain unchanged, while others must adapt depending on the size development.
In short, even if it’s hard to fully explain without showing it in practice, footwear grading involves constrained and unconstrained zones. Trying to manage this in a parametric system often results in a feature tree that no longer behaves as expected. In Rhinoceros, this problem does not occur.
That said, I would still welcome parametric tools in Rhino — I’m not against it. I come from SolidWorks and I use Cimatron for mold design, so I understand the logic behind parametric workflows. But Rhino allows you to work effectively in situations where more “renowned” and supposedly “intelligent” software often fails — or rather, where it promises efficiency that in reality is mostly marketing. From what I see, these claims are often exaggerated, especially when presented to clients.
Even if I can’t show much, here are some examples: with parametric modeling, it’s not that you couldn’t do it — but what I can complete in one day, including all variations and adjustments, would take significantly longer in a parametric environment, especially when dealing with complex surfaces, patterns, or textures.
Take this sole as an example: you can’t simply scale it and be done with it. First of all, the heel seat area — where the heel rests — scales in one way and has to maintain specific draft angle constraints, while the area where the ball of the foot rests scales in a different way. The heel is a separate part and also scales in a specific way in X, Y, and Z, again while maintaining the draft angle constraints, whereas from the halfway point downward it stays the same and only changes every two sizes in the grading, so it scales in pairs. The cylinders must be constrained, meaning they keep the same length and must remain perfect circles, but they change position. To put it simply, if I had to do this with a feature tree, you just wouldn’t do it… or at least, in the end it would be like using a non-parametric CAD anyway, because the command tree would simply break down.
If you want to see everything they’re currently working on, check this page. @ArtProgTech
Among other things, I also used the new Patch command in Rhino WIP on this personal project that I work on as an exercise in my free time.
