XNurbs releases a ground-breaking NURBS software

Rhino’s greatest growth potential is in Architectural design. It makes zero sense to develop costly commands that will satisfy a niche market. It’s a great multipurpose tool. It does a broad range of things really well. It’s unrealistic to expect it to compete with specialist Cad modelers like Alias or Solidworks.



@davide76, I too would have preferred to see more usable surfacing tools in Rhino but also realize that McNeel has to follow the money. There are some good plugins for Rhino like VSR that do address some of the deficiencies in that area of design and some others that hopefully will deal with a few more.

I wouldn’t fault McNeel if they did an evaluation and determined to focus solely on architecture if that is in fact their bread and butter market. There will be other products that are introduced to fill the gap, supply and demand.

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A quick try. However, one can clearly see that a few CVs need to be subtly transformed for a final result.

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Hi Toshiaki_Takano,

If we release the plugin, it should work for both V5 and V6. (The plugin is surprisingly simple, so it should work for both.)


Please send models in IGES or STEP format. From your image, it appears that the result has little to with NURBS, and looks like a part of a sphere with a pole (degenerated surface). All CAD systems try their best to avoid the degenerated points. For a sphere, the best result is to use a sphere. Thus that example may not be a good example for testing NURBS (some software may actually use a trimmed sphere).

Hi all,

XNurbs is “one for all”, i.e., one simple UI to solve all kinds of problems for NURBS creations. We do not optimize XNurbs for any particular application., e.g., Patch or multiblend etc. To get better results for your applications, you should add additional constraints (i.e., you can use internal constraints to control the surface shape generated - please read the following comments to TomTom and Lagom.)

XNurbs generates the lightest surface by default (i.e., the surface with the smallest number of control points or non-dense control points. For MCAD, the less control points, the better.). If you prefer better surface quality, you need to change the “Quality Control” and “Relax Precision” options.

“Not by trying to fit in a single patch surface by some boundary conditions, but instead by choosing a logical patch layout in order to reduce open edges down to 3 or 4.” Or “VSR”

The method of splitting a single surface into multiple surfaces was also used by big CAD companies in the past. However, this method was abandoned by big CAD companies after 2007 due to some flaws.

TomTom and Lagom
If you are willing to spend time to draw additional curves, then you can simply input these additional curves as internal constraints into XNurbs, XNurbs will produce a single patch surface, which should be superior than your current method. Could you send me your constraints (i.e., boundary conditions) with additional internal curves (i.e., your layout)? I will send back the generated surface and you will see for the first time what variational tech can do for your design. (XNurbs can handle arbitrary curves and points as constraints.)

If you would like send some models, please send them in IGES or STEP format. SolidWorks cannot open some 3DM files properly. Also do you guys have any new design mode or new design styles? (Since XNurbs does not restrict how a surface can be generated, so users are free to use the most suitable method or any constraints for their work.)

Great. Price maybe reasonable if it can support both V5 and V6.
It would nice if you guys can set up a forum as this, to get feedback into the product for couple of months after release of plugin.
Thank you for the reply. I think I’ll try and install solidworks and try it out.

Test: https://www.youtube.com/watch?v=w6mQPnX9P_I&t=48s
If anyone wants to try … I have little time for now …
And this: https://www.youtube.com/watch?v=oZQ1Hv48x6A

In my daily experience, nothing beats SolidWorks when filleting, so I find it much more effective to do the explorative design and definition in NURBS and simply fillet in SolidWorks in the end. Even in a small industrial design studio situation, you need parametric capabilities to deliver top quality on time and on budget; filleting is not an exciting hobby to be explored with academic leisure.

Every hour you can’t bill the client counts. You want to be at the pub at 5pm after all ; )


Yup… nothing but perhaps Creo. :smiling_imp:

In all seriousness, seems to depend on what specifically one throws at it.

Sometimes, but not often, one will work and the other will crap out. Creo seems to just eat up and work on stuff that your better sense says just should not work. Efficient time saver.

Fusion is improving, but not yet up to Creo/SW. In comparison as a fillet machine, etc., incredible value.

FWIW - none of them can do what Rhino can do as well; in totality that is…not a specific tool, etc. It is a symbiotic relationship, IMO.

So if it is compiled for 6, the modern way McNeel recommends, the plugin will be released for Mac too, right?? Because it is relatively simple, right???

Don’t let me (us) down, please… :pray:

Broken free from Windows as daily driver. Only go there when necessary, and not sure XNurbs fits the criteria to invest. (If I have to do something I don’t necessarily want to do.)

Hi ec2638,

XNurbs is quite simple, but it is powered by XN Kernel, which does not support Mac. So XNurbs will only work for Windows. Sorry.


I upload a model downloading from the “How to make good smoothing?” post in the Forum. The original model is not good. Requirements:
Position Tolerance: 0.001 mm
Curvature Continuity
As shown in Preview.png, an additional point constraint is added. (You can use internal constraints to control the surface shape generated.) “2.igs” is the generated surface.

Patch is a trivial application for XNurbs. If you have models for other applications, please upload them in iges or step format. We can send back the generated models.



2.IGS (228.9 KB)

OUCH! Would have likely thrown it into the toolbox if performed.

We already know how to model and have a deep toolbox, so didn’t necessarily need a ‘Magic X’ button. Still, always nice to pad the bench (sounds interesting) and Rhino needs some modeling love going forward, IMO.

Assumption now is that toiling with Windows not going to be worth it for the ‘Magic X’, when the obstinate desire is to limit Win exposure. Likely find another way at job 1 by the time I do the Mac-Win hoop jump. We’ll see.

Good luck, however. Thanks for the clarity.


PS - Why have I never heard of XN kernell?

That’s a pretty good result considering that the input geometry is crappy and importing into SWX makes bad even worse.

I imagine that your software might do a lot better if the input geometry was of better quality

Here is a file with a little better geometry.
2x.igs (129.3 KB)

Even the Rhino Patch function can be persuaded to make a half way decent surface with better inputs.


Hi ec2638,

XN kernel is a proprietary kernel, and will become available after we announce XNurbs to SolidWorks community. XN kernel only has one functionality: generating NURBS curves/surfaces based on energy-minimization method. No existing software can match its capacity in the field.

Hi Jim and all,

Yes, it does a lot better with your input. Position Tolerance Requirement is 0.001 mm.

“Preview2.png” shows that only four curves are selected. To make it a bit fun, the internal curve (Curve 4) is cut short and leave a gap with other edges. This creates a lofting/sweeping-like surface with curvature continuity. (@jim : Your additional curve is the right constraint one should add.)

Filled2.png shows the Zebra view and Filled2.IGS is the generated surface.

Filled2.IGS (110.6 KB)

3(lightest).IGS is the surface generated from six curves.
3(lightest).IGS (133.1 KB)

Even though the generated surface is much better, some edges from the existing model are bad, and the original designer should fix them before moving forward.

I can see that professional designers are willing to spend time to draw additional curves. If so, XNurbs can definitely create superior results. If you don’t want to show your design to the public, then you can send your models to ‘support@xnurbs.com”. We will send back the surface generated by XNurbs. (Your model should contain the additional curves and points you would like to use.)

That’s really very disappointing…


Apple’s bootcamp is your friend; Apple MacBooks run Windows 10 really well (apart from draining the battery faster than under OS X) and with Paragon HFS+ (Windows 10) one can see/read/write/backup the OS X partition. Just buy another Rhino license for Windows.

No it’s not :slight_smile: I tried that when I bought my first MacBook (2009) and used Rhino only on the Windows side. Bootcamp even made opening OS X slower… and I didn’t like moving between operating systems at all. Now I’m using OS X on my home computer - which in a near (?) future is going to be my main work computer. Until then I still use the windows version daily also… but not for long. Despite working in Windows since 1991 I like the Mac much, much more. There are so many things in Windows 10 that really irritate me on a daily basis, but that’s another story…