Class A surfacing tools

Continuing the discussion from Welcome to Serengeti:

HI Naresh

I m sorry to say this but your knowledge of Rhino is probably limited. Rhino is a NURBS modeling package just like Solidworks or Catia, Alias etc…Therefore the precision is the same.

It does achieve class A surfaces ( meaning curvature continuity surfaces ) Class A is just a fancy term to say surfaces exposed to the viewer. Therefore they have to be of good quality by opposition to class C surfaces that are just structural and beneath the viewer s sight.

I work for a major aerospace company for 15 years and me and my colleagues work with Rhino and do some Catia if we need to. We surface exteriors as well as interiors and work closely with engineering all along the design process.

We design and prototype and also render all with Rhino and we all love it.

You also have a tendency to confuse the desire to have a specification tree like Catia or Soliworks. The reason there s a specification tree it s because they re both parametric tools. Rhino is a freeform surfacing tool meaning you can pretty much surface anything you want without being imposed constraints right from the beginning.

And to me that s a big plus.

Hope this helps



Just making assumptions on other people’s points reeks of arrogance and a healthy dose of ignorance. I didn’t even want to write this to avoid getting into a mud slinging contest but your pointless remarks are more than inviting such a response. Did you even read my message? I do know extremely well that Rhino can produce Class A surfaces, but do you know anything beyond that? Do you want me to drill holes in your email? Did I mention catia here or solid works or Alias?

Ok, so how many of the aircraft from your company have you designed from scratch to production in your 15 year career? Can you really define what class A surfaces are really (are they just curvature continuous)? Have you ever done a complex geometry in Rhino with lips and flanges and skins etc, taken it from design to development to machining to prototyping and to production?

Kindly do not make insulting suppositions till you understand and read correctly what is written.

Thank you,

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Woah sorry you feel this way. I wasn t making any harsh comments.

Please could you explain better to us what do you mean with Class A tools?

Did you know about the history button? In v5 it can keep sweep2 also and in wip 6 blend and match.


I understand that Rhino is able to make Class A surfaces, but for some reason other folks in the industry have the impression it can’t. Does anyone really understand why this is?
Alias is almost always used (mostly because of my industry) as an example of a software that can create Class A surfaces during this type of conversation. What does Alias do when creating a surface (from the users perspective) that might be missing or not conveyed well enough in Rhino?


Rhino can create so-called “class-A” surfaces just as much as Alias does - the underlying NURBS mathematics and geometry is the same. The difference (as far as I understand it) is that Alias offers a better set of tools for working with these surfaces and keeping things matched, curvature continuous and easily editable. That is what the VSR plug-in brought to Rhino, simply better tools for these applications than the native Rhino ones, but they still worked on Rhino’s core NURBS engine. So Rhino is capable of making/editing surfaces every bit as good as Alias, ICEM, etc. - simply that in many cases it can take a lot more effort to do so using only Rhino’s native tools. And in industry, any tool that saves time and makes your job easier on a daily basis is generally worth the investment.



My point number 1 in the request to the Rhino6 development team is exactly what Mitch has alluded to… I did do the initial testing of the VSR plugin at the time it was still VSR, and liked what I saw… unfortunately Autodesk bought them and I retracted my decision to go for it. I still have to use the TSplines since there is some historical material already in TSplines and we’re current with the releases with the most recent update. Besides TSplines, is capable of doing things that I’ve yet to see in most of the software we use. VSR was great but still did not give enough control over the surfaces that could mesh with my workflow.

I wonder if anyone in the Rhino 6 development team has used NX’s Studio Surface or ICEM surfaces? For us the ideal solution would be to have VSR like capabilities along with a localized history tree of the areas that depend_on or those that affect the model based on some critical surfaces. The “history” is a truly lame tool for that purpose. Now, I didn’t for once want to give some solution based request here, since the Rhino Development team knows the limitations and advantages of their own environment better and therefore, could come up with an integrated solution that could be a huge positive surprise to us.

The second point I had was: lets say you’ve got an intersection between two surfaces, the control point count on that can be excessive. We usually have to had edit those points, if we want a 2 curve sweep so that the sweep can be reasonable in its weight. There should be some way to lighten such stepped flanges, tongues and grooves that could be joined to the surfaces within Rhino itself.

Its not to say that Rhino cannot do this or that, its to request the team to have tools that allow better control over what Rhino can model. In that respect, try to give us a better class A control tool set, such as the VSR tools, that is well integrated part of Rhino6.

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@naresh is correct.

That’s maybe the goal for V7…
I guess those tools are the only improvements that Rhinoceros can lastly make. Otherwise, a perfect tool to get things done. But, still a ton of work…

I don’t know what to expect after all those development.

BTW, T-splines cannot make above G1 continuity surface.


Technically you are right about the G1 continuity, but that’s only at an infinitesimal star point of the TSplines. A good explanation of this is on the following thread:

In real life, here’s what I’ve seen. We machine our parts modeled in Rhino and TSplines (using TSplines in many secondary and organic areas) and even with our 0.001mm precision machine, we’ve not noticed any issue with reflections on the star points as you’ll notice from the software analysis using curves of the extracted nurbs on the star points. One thing we try to do is to limit our Star points to geometry that has a simpler curvature. But our machined parts have reflections that are perfect to the eyes of anyone who’s seen them. Therefore, the star point’s microscopic discontinuity does not seem to have a measurable error on our real parts/molds/master-plugs etc.

TSplines do give excessively heavy intersection curves if one needs them and often the control over position is an issue and this is an issue for us. Many times our final models go beyond a few gigabytes and that makes the system crawl. Another thing, if we use the TSplines thicken command, we get a better model, less weighty than the Rhino thicken that is based on offset surfaces. The TSplines offset is not very mathematically precise but its precise enough in the engineering sense, where the parts will be machined as master plugs etc or 3D printed. The biggest advantage is the control and handling of that thickened, or for that matter any large closed, surface done in TSplines vs. the Rhino model that would now become very heavy and unmanageable.

So we use TSplines on all the ledges and lips and tongues, but its not ideal, an integrated Rhino solution would be more appreciated. But I’m sure that Rhino people know this…

Hi alexandre_galin
l work with Rhino & AD Shape modeling for Rhino at car Design . I have question for you . Do you know any car design Company that work with Rhino with high quality surfaces ( A Class Surface) ?

I’m not alexander galin, but I do work in automotive. Rhino is indeed used in automotive for a wide range of tasks, such as automation, interface design or even on rare occasions on concept design. Almost every product design student is learning it. So it is a very common and a valuable “assisting” cad software and I believe I can speak for any car company, it is used everywhere.
However for “traditional” high quality surfacing it is not used. (depending on what you understand under it)

It is true, you can create class A, especially with Virtual/Autodesk Shape Design. However the ability to create class A surfaces does not mean you get the surfaces to the right locations in a certain timeframe with the same parameters as you would expect. Imagine you get a car part from another company, how can you ensure reproducing identical surfaces on your part if company A uses Icem Surf and company B uses Rhino+VSR, because one aspect of class A is to get an homogenous appearance. A Filletblend in surf is different to a Filletblend produced in Alias. Of course you can modify shapes again, but this is insane.

So VSR was and still is great, but being in high end industry you need every functionality or better if you like to replace another software. If you have 70 % of Icem Surfs capabilities its simply lacking 30 %. So very often a car company forces you to use a certain cad platform to get the job done. As a freelancer you might even get a temporary license for doing the job, but they want you to use the desired software. Oh and don’t mix up class A with class A. Even in automotive some concept designers believe they produce class A, but in the end other completely overwork their work. So that is why some car companies even switched to mesh modelling software for concept, because in the end you need to completely overwork it anyways.


hi yes I know some using Rhino to surface cars. It s not the big car companies per say since they have their own applications i.e. Alias, Catia, ICEM etc…but I ve known a few who an do amazing surfacing work with Rhino and have a prototype made. I also know of one engineer doing what we call Masterlines ( aircraft surfaces ) using Rhino for the small jets market.So yeah it is used. With VSR you get even more possibilities but you must know by now that VSR will not be supported for Rhino anymore :frowning:


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