Hi,
Can Rhino create the same quality as Alias while you don’t use any SubD plug-in and just use its native curves and surfaces?
Which one would give you better control?
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No Rhino cannot create the same quality. Rhino lacks the matching tools and more important Rhino has no analysis tools for class A surfacing.
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Well, for what exactly? “Class A” is a meaningless marketing buzzword.
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In my experience yes, but it takes more time and there is no good history implementation.
But Alias can do 1 thing, rhino is much more flexible.
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That’s not true. There are methods and standards to Class A.
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in danger of creating a shitstorm… the term class a is originated in automotive industry. its by no means a marketing buzzword however talk about gets very religious.
for a long time even alias wasn‘t the tool for class a in automotive. I never heard from a german car brand that made final surface models in Rhino. Last year I even saw Tesla looking for people doing class a with icem surf. Industry standart for class a surfacing is still Icem Surf. However Alias is getting pretty close and some oems already replaced it for class a.This is also because Icem Surf isn‘t develloped much further.
Now the problem is that a lot of people don’t really know what it is,because they never did it professionally (in automotive). If so nobody would like to do class a in Rhino although you can create very good surface models with rhino.Out of question!
But:Applying principles of class a doesn’t mean to model in class A. As Cadworx said, in Rhino you cant even analyse if you fulfill criterias of class A and that is the most important aspect.
Its also a misbelieve that class a means that it is superb modelling or that is always needed.Its basically just very accurate modelling, controlling light reflections for objects with highly reflective materials. Most modelling is done in class B for invisible and technical parts. It can get very boring and its not always worth the effort. I also must admit that no every rule makes sense. But comparing Rhino with Alias and Surf or comparing Subd surfaces with nurbs patches is like comparing apples with oranges and you should definitly stop doing these comparisions if you dont know both worlds
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That’s true but it existed as a tooling classification and standard and was used long before there were CAD programs and anybody was babbling about G2 surface continuity.
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VSR Shape adds the tools to do Class A with Rhino.
this is true. G2 isn’t everything and I’m one of those few in this forum who constantly say that there are situations where a good g1 transition is better as having G2. This is also my critic on Sub-D, because it assumes that if you have g2 everything is good (although Autodesk indeed points out the weaknesses and even says that sub-d is basically just for concept design, but for this stage its powerful).
Yesterday I was bit harsh. So @JimCarruthers has also right in terms that class A is misused as a commercial buzzword, in a way that a lot of people claiming to produce class A, but they actually don’t.
@Stratosfear: You probably know this, but VSR is dead and there is no recompiled version for Rhino6. So sadly there is no “class A” - plugin anymore. Besides that, VSR wasn’t fully complete. Some vital functionality was still missing, however analysis tools were great
Autodesk/Alias on what “Class A” means in the auto industry: https://knowledge.autodesk.com/support/alias-products/getting-started/caas/CloudHelp/cloudhelp/2018/ENU/Alias-Tutorials/files/GUID-64611955-D2CC-44F2-98F0-D4F1FE931D8B-htm.html It is significant that they talk about the refinement to Class A occurring at the end of the design process.
Discussions about “What is Class A surface quality” and “How to achieve Class A surface quality” seem to be frequently confused and mixed together. When the overall surface is released so that tooling can be made my guess is what matters is the quality of the surface and its conformance to criteria, not the details of how the patches are organized, the degrees of the surfaces, whether single spans or multi-spans are used, etc.
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Hello, I think Rhino and Alias are incomparable at any way! I use both, also I use VSR Shape, and according of my point of view these softwares are designed to achieve different goals. If you want high quality results with lots of explicit controls, then Alias / Catia is your software, if you want flexibility and speed then you should choose Rhino. Alias is designed for comfortable work with CV-s, Rhino is not! Even VSR doesn’t have good CV manipulation tool. Compared to Alias’s one, they are incomparable. Also Alias has Explicit control, which mean control over the quality of the surfaces at every stage of modeling process, Rhino doesn’t have such functionality. Alias is well designed for manual (direct) modelling, Rhino is not. Direct modelling is essential for achieve high quality results, where automatic tools fail is the beginning of manual tool i.e. the hand 
There is no Class A without direct modelling, but this scares a lot of modellers, because it requires a lot of practice to “feel” the proces for itself.
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Yes, but all these points help you create the cleanest and most manageable geometry while on your journey to an acceptably finished part, which often involves many modifications from the designers and engineering input for feasibility (the cleaner your model, the quicker you can modify).
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How is Rhino not designed to work with control points?
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Hi David - I think it’s more the UI for doing this - how smooth and convenient the motion of the points, the feedback from changes, useful constraints, that sort of thing.
-Pascal
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After five years I’m reposting the question from the initial post. Is Rhino now on par with Alias?
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It’s a pointless question:
- Rhino and Alias are both mature products that have their own user bases and markets, and those are not at this point ever going to change unless something new comes along and kills both. Also related, at this point Rhino has nothing to “prove” in some online measuring contest. It’s also never going to get into automotive design studios(though it’s in fact used throughout the supply chain) because of McNeel’s BUSINESS MODEL, they are not equipped to go after giant enterprise customers.
- “Class A” is a meaningless marketing buzzword. YES, IT IS. It means “whatever feature the Autodesk salesman is trying to pitch.”
- When you actually interview somewhere like Apple where they’re super-obsessed with surfacing quality, they see Rhino/Alias experience as interchangeable, and they tell you that their workflow is simply brute-force point-pushing surface sculpting–what Rhino 1.0 could do!–not gimmicky “tools” for making a silk purse from a sow’s ear.
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And there’s probably no need. Rhino’s price can fit within miscellaneous expenses in a designer’s corporate card. I always advice colleagues working at companies with strict CAD dictatorships to say they need Rhino as a 2D-3D translator for Illustrator, PDF, and mesh objects and it costs so little that there’s no point arguing against it.
There is no reason not to own a seat to Rhino for a corporate designers, regardless of what other tool they use primarily in their pipeline. Keep in mind all MCAD tools are extremely slow and cumbersome when you just want to tinker a bit with something.
G
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We get your point (you have made it repeatedly) and there surely is some truth to it.
But it is also an oversimplification and generalization, that doesn`t hold up to scrutiny in all cases.
There are fields where “class A” has a specific meaning and is connected to distinctive methods and processes.
In other fields it certainly may mean “whatever convinces you to buy our software”.
And to answer the question of this topic:
No, Rhino is still not on par in surfacing tools to achieve and manipulate high quality surfaces like you can in Alias.
There are several threads that list the commands, features, functions that are missing.
The main ones are: better surface matching, explicit control of degree/spans in all surfacing commands and better control point manipulation. (see said threads for detailed description)
(edited for typo)
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Show me (any) final ‘class-A’ (manufactured entities), and using a measuring tape and protractor I’ll prove to you it’s a buzzword in all cases – [(+/-0.03125 – +/-0.0625") at best, if not worse.]
What are the GD&T(tolerances) of “class-A”?
How much control does a CAD operator have regardless of software? A CAM operator regardless of softare? A CNC operator regardless of software? A mold and die stamp former post processor? An assembly line worker, painter, buffer? An autobody repair shop?
If ‘class A’ actually existed, and our universe had perfect symmetry, then hydrogen would have never accreted to form any other element – let alone hydrogen it’s self. Therefore, class-A doesn’t exist.
Unless ‘class-A’ means +/-0.1875" — then maybe it does exist. In which case, it’s up to the skills of the operators down the line (regardless of software) to the end of the manufacturing process; all following the allocated GD’s&T’s to the very end, and the repair mechanics going forward.
The last thing one needs, is a repair mechanic installing a bumper wrong, after a fender bender, on a ‘class-A’ machine +/-0.25". 
The repair mechanic could just ask the customer, “did they use Rhino or Alias?” 
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It’s not about the overall tolerances of elements as a whole.
Even if the fender of a car is off by, say 5 milimeters (let’s not use archaic units of measurement, shall we?) that doesn`t change the fact that surface discontinuities within the surface would create unpleasant highlights.
The same is true for moulded plastic parts. You may find fairly severe tolerances due to shrinking or other factors, but still slight discontinuities remain visible within the surfaces and may ruin its appearance…
And of course whole industries who invest in expensive software and more expensive training of their modelers are just too stupid too understand that all off this serves no purpose whatsoever and happily throw away millions of investments in useless software.
If only they’d asked the cad/cam dude with the protractor.
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