XNurbs releases a ground-breaking NURBS software

I myself had personal contact with some of the VSR staff.
I have no information about what was going on behind their acquisition by Autodesk though.
So I was only guessing and I may very well be wrong.

Without substance? Irrational? That surely is more than debatable.
Seemed to have been working quite well for some companies in the last 20 years, making millions or billions of dollars in the process.
I am not saying it is a generally good idea (I honestly can’t tell), but it surely is tempting for a lot of people when you look at the successful examples.


Just want to see what kind of surfaces you are looking for. The Quality Control for the model is set to the lowest. You can improve its quality by adjusting the Quality Control slide. Also you can further improve the quality if you could split the surface into several surfaces (I guess no one would make such an effort.) Of course, 0.0002 mm is for g0 position (note "mm"). G1 deviation is set to 0.1 degree. (Of course, it can be set to 0.01 degree by changing one line of code, but we need to consider if it is necessary.)

However, filling/patching is a trivial application for xNURBS. There are numerous operations or scenarios how XNurbs could be used - one UI for all operations. For example,

Multiblending/Lofting with G2 Continuity (5 edges)

Y Lofting with G2 Continuity

Network of Curves

We need some demos to show different operations/applications done by XNurbs. Could you guys provide some examples via our private emails, which could show the use of xNURBS in other operations/scenarios? We won’t share your models with others, and we only need to use your models to generate screenshots similar to the ones above. When we use the screenshots, we will state clearly “Courtesy of XXX”. Thank you in advance.


I took a look at the VSR model you showed. Some comments about VSR (not very good in terms of performance, stability, easy of use) are actually correct - VSR’s method is based on the simple idea: try to split a patch into multiple quad-sided surfaces. This method was developed in 80s and 90s, but all major CAD companies abandoned this method long time ago, and none of major CAD companies uses this method due to its poor results generated by this method… If you want to know the details, just ask why major CAD companies’s R&D teams abandoned this method.

Nervelessness, as stated above, filling/patching is a trivial application for xNURBS, so we don’t want to focus on filling/patching.

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Look, I’ve been using vsr for a long time now and all these complaints (performance , stability , ease of use) don’t sound legit to me. It’s as easy to use as rhino is, performance is excellent (on any decent machine) and yes the only one that might have some merit is that it crashes once in a while. (rhino crash save has never let me down so it’s not a tragedy for me)

As far as multiblend goes it’s still there in Alias 2019. (not abandoned then is it?)

It’s not even about the patches imo, I prefer to have 4 single span surfaces to 1 monster surface, but I would like to have both options really.



When’s the next target Beta release date?!

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Well, Multiblend wasn’t the best feature of VSR. Regarding performance / stability, what does that mean? I never encountered such issues with VSR. If it failed or crashed, it did not kill the running Rhino Instance. If you feed in crap surfaces you cannot expect good surfaces.

Volkswagen, Audi, BWW, Mercedes … They all still using these old fashioned methods.
A car skin usually is made of pure Bezier patches. Funny, leading software here comes from Dassault (Icem Surf) and Autodesk (Alias). Autodesk bought T-Splines and VSR and they integrated its functionality (Speedform,Fusion360,Alias). VSR devs were former Icem Surf devs. Dassault integrated Icem Surf into Catia -> ISD.

If we speak about parametric functional geometry you are right. But seriously, no one doing functional parts is looking at controlpoints and highlights.


I just tried Xirus Patch tool on this, had to remove the degree 3 curves from the IGS and convert the 5th degree ones. Let me know what you think:

FilletXirus.3dm (2.2 MB)




impressing as well. Even better as XNurbs here.:+1:

Wondering if control points can be reduced.

However, this is an highly idealised example. Maybe somebody posts a more practical situation to solve.

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Hi @TomTom,
One of the advantages of XirusCAD is that control points greatly decrease and represent known properties: interpolation, tangent planes and curvatures. The resolution of the final shape can be adjusted for a desired precision. The plug-in is in Alpha phase and offered for free for testing & feedback. Try it out!



I own VSR, I don’t think I’ve ever got a result that’s better than me manually sweating the details by hand in Rhino. I’m optimist enough to still try in sometimes but it always returns poor results. Consistently. Many times with naked edges too, just like Alias.

Maybe this is just me, and because I only try it on hard stuff. So I could either be really unlucky or really inexperienced and I’m the only one dissapointed with it. Out of its 137 users worldwide. Or maybe I have higher degree expectations than all the VSR/TSplines fanboys here.

First of all VSR Tools is incomplete. A lot of its functionality is technically seen nice, but has little practical meaning, such as Multiblend and many of the Scan-to-Surface functionality. However the Analysis part is of much higher importance. Static highlights,Deviation analysis etc. Other important functionality is basic functionality like surface split,curve projection or improved control point tweaking.Looking unspectacular, but very useful. Its the opposite development of most CAD development which targets on automation, which almost always comes with drawbacks. Automation means to swap controllability and quality for speed. Its more popular as well, it promises higher efficiency.

It think we agree on the fact VSR usefulness was not communicated well enough. VSR is enhancing not replacing native Rhino commands. But if you lack the specific knowledge about this tool it doesn’t necessary mean that this tool is bad. The issue with class A modelling is, that you need to know its principles. Approximation over Interpolation is one of them (->naked edge problem)

If you don’t know and apply them, maybe because you don’t need it or you don’t know them yet, you’ll come to the conclusion that its worthless. And it definitely is for many applications.
But once you know it, then you won’t like to model specific shapes in plain Rhino, because its way too complex and slow.

If you ask me, Since Rhino is a direct modeller, I prefer a further development regarding shape quality and better analysis. The focus of both X products is improving efficiency. But looking at the cps you clearly see the tradeoff. Since working with heavy surfaces leads to problems further down the stream, a low CP count improves efficiency as well. So what you save on work in first place, will catch you later.

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Hi Gustavo,

I’m not VSR lawyer or apologist, just credit where credit is due.

Is it possible for you to show us some of these “super difficult” conditions, im really curious…


When will we have the pleasure of trying out a stable version of this Rhino plug-in? I think it’s been almost a year since his announcement …
Can we do this by the end of this year?

There won’t be any Beta release. (If you read the SolidWorks forum, “xNURBS has proved invaluable both for quick design phase surfacing for concepts and final production surfacing. So far it has been very robust…” So there is no need to ask you to test it.)

When we release xNURBS, it may not be available to everyone - buying xNURBS may need get an approval from us. We only develop the plugin to deal with others future aggression - others may mean some big CAD boys. People in CAD already told us that ‘our technology is too good, and things could become ugly if …’ The plugin is quite different from other Rhino plugins. We will work hard to get it released next month.

Did you read my post above: We need some demos to show different operations/applications done by XNurbs. Could you guys provide some examples via our private emails, which could show the use of xNURBS in other operations/scenarios?..

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It really starts to feel ground-breaking…for XNurbs

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I really spend way to much time on thinking about what to answer to that post… You should definitely hire somebody who knows more about marketing :slight_smile:


Same here @TomTom. Thank you for saving me from myself. Out!

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XNurbs: Software development with an attitude…


Bigcad is out to get him

Ok… thanks.

So in summary you’d like rhino users to post surfaces creating issues so XNurbs can use it
to enhance for people who you give approval to and likely not rhino users?