There was a very nice thread showing how a VW Beetle was modeled in NURBS here:

http://forums.polyloop.net/travaux-cours-finis-3d/1765-vieille-cox-nurbs.html

Although it's in French and modeled in Amapi, you could see how curves are strategically placed to support every surface applying a combination of tools. This actually sparked the thread I started several months ago about the need for a Network Surface tool, if you remember. That's the time when the Network surface tool was born in MOI. That thread probably precipitated it. I used the back of a computer mouse for a sample, though. Lol.

Sure, not everything in the Beetle thread is Network-applied, but you could see that the techniques used are very translatable to MOI.

Hi Blend.....

the link is broken for me....

re. broken link - the whole of polyloop is down at the moment. They have just changed to a new server so maybe it is teething problems ? Give it a couple of hours and try again. (Hope it gets going again soon as I am also interested in this thread).

Hi,

I have found a few "the making of" articles about modelling cars with nurbs in Rhino here at http://www.suurland.com/
Look in Portfolio section and have fun.

Bogdan

Try this one:

http://www.carbodydesign.com/

Look under 3D tutorials for both NURBS and Polygons.

Polyloop is come back!
Curiously tutorials archives are empty of images?
I will ask to the administrator why
Old Cox
original thread is here http://forums.polyloop.net/travaux-cours-finis-3d/1765-vieille-cox-nurbs.html

Try the link in my first post which is this one:

http://forums.polyloop.net/travaux-cours-finis-3d/1765-vieille-cox-nurbs.html

Hi Bogdan,

>>All I can say it is time consuming and I think I'll stick with Sub-D modelling for complex models such as this one

I can understand some frustration when attempting such models, but it is more a case of finding direction to produce a model with the tools available.
Most tutorials for car building in nurbs are based around Rhino, which IMHO is one on the best surface creation/editing programs, but even having that program does not then give the user the ability to build such models, only more advanced tools.
I have played around quite a lot now with MoI and do push the program, so maybe I can help out?


>> and do the stuff that MoI is ment to do in MoI :)

That is a little concerning to me, as I always prefer to do what I want/can in such a 3d program, not what I am told I can do by some limitation due to missing tools.


Let me have a look around for some car blueprints that others can also follow (and that will not be too time consuming) and I will start a WIP for a car.


Regards,

Hi Steve,

> That is a little concerning to me, as I always prefer to do what I
> want/can in such a 3d program, not what I am told I can do by
> some limitation due to missing tools.

I'm surprised this concerns you - there really isn't any one single program that exists which contains every single possible 3D design and analysis tool combined within it.

All programs are missing tools of one sort or another. If one program works better for a certain particular kind of process or certain kinds of shapes, then it will probably work better to use that program for those particular kinds of things.

That's just a pretty normal process, I mean if you want to hammer in some nails use a hammer for that, not a screw driver or a drill press. Does that mean that a drill press is useless? No, not at all...

- Michael

Hi Micheal,

Maybe you misunderstood my reply to the statement made?

I can basically produce any model I want in MoI that I can in Rhino, it is just a case of working around some missing tools.

Please re-read and you may see what I meant. If not, then maybe I made an a statement not understandable?
Please take my comment in respect to/as reply to other comment

- Steve

Hi Steve, sorry I have misunderstood you there.

I'm not sure I follow which part is a "little concerning" then, is it something related to MoI's development which you have mentioned in the past, or do you mean you are concerned that Bogdan may have made an incorrect conclusion?

- Michael

Hi Micheal,

>>I'm not sure I follow which part is a "little concerning" then,

That Bogdan has MADE an incorrect conclusion.

My "little concerning" was based on the statement:-

>>"and do the stuff that MoI is ment to do"

That is why I was going to build a car in MoI, and show its construction. My only problem being my available spare time, and finding a model not too complex that it causes more question than should be.

Maybe just not bother eh?

Hi Steve and Michael,

Thanks for taking your time to reply to this thread.
The reason I have started this thread is that I wanted to know more about building complex models using nurbs and I have thought that will be helpful for others that might happen to be interested.
I have picked as a subject a car, for the reason that if we look around, almost everybody, when do start 3D modelling, you guessed it... is gonna pick a car as a subject.
By no means I have ever underestimated MoI in any aspect, since I am well aware about its tools and to be honest, I really love it.
I could have picked a much more easier subject, like a WV Beatle for example. But I wanted to push my skills and MoI as much as possible and I have picked this BMW M5; here is the blueprint: http://www.the-blueprints.com/index.php?blueprints/cars/bmwcars/10989/view/bmw_m5__e60_/

Thanks again.

Hi Steve, I understand you now, sorry I leapt to an incorrect conclusion there.

A sports-car type thing does tend to be a pretty difficult thing to do, there are many aspects of it that are kind of similar to sort of face / character modeling that sub-d is so good at, like it tends to involve kind of organic shapes that need to blend completely smoothly together in many different directions.

That kind of full-directional blending happens just automatically with sub-d, so some of the same things that make subd good for faces also make it kind of easier for this as well.

But it does seem that most of the people who do a whole lot of car design stuff actually do use NURBS for it, but I think it tends to take a more carefully thought out modeling strategy to make it work well.

Once you have some experience in those kinds of strategies, then some of the NURBS type design tools can let you go quickly at that point since you then build kind of individual panels of the car really quickly from some curves instead of needing to do a large amount of individual point manipulations.


The tricky part is that for someone who already has a background in sub-d modeling, they don't have to adopt a significantly different strategy for doing the car, but for NURBS modeling it takes a lot more new strategy learning.

It kind of demands the more advanced type of NURBS modeling where you are working on an individual surfacing level and not really at the solids and booleans type level. The solids and booleans type level tends to be a lot easier (lower learning curve I mean) for someone to get up to speed on who is not familiar with NURBS. A car is more like jumping directly into the deep end right away...

- Michael

Hi there :)

@manz

I'll be more than interested by your workarounds and tips about creating a car in MoI !!!

...

My frustration actually is that since I have discovered Nurbs (thanks to MoI), I really don't want to go back to polymodeling for any hardsurfacing model ... really never. It's not only a matter of taste, it's just that surface coming from sds technique are so inaccurate, reflections are never perfect as they can be when using nurbs.

As Michael said, maybe I should just build the model without the continuity for now, and wait until new tools are integrated in future release of our favorite modeler :o).
If I have to build this kind of model for my professional work I'll probably buy Rhino, seems to be the best companion of MoI ... I'm not sure to make the jump for a more advanced nurbs package for my 'hobby' daily models :S

< Let me have a look around for some car blueprints that others can also follow (and that will not be too time consuming) and I will start a WIP for a car.

This one has neat blueprints & method ;)
http://www.etereaestudios.com/docs_html/nixus_htm/nixus_index.htm

Hi Bogdan,

> I have picked as a subject a car, for the reason that if we look
> around, almost everybody, when do start 3D modelling, you
> guessed it... is gonna pick a car as a subject.

Yeah a lot of people actually pick a human face as a beginning subject too, but that is also a really difficult subject and another one that is especially well suited for poly/sub-d...

One technique that can work pretty well for this kind of thing is a sort of hybrid approach, where you start in NURBS tracing curves, and sweep some panels out to get some basic forms in place. Then convert those into polygons and take them into a sub-d modeler and do further refinements in there, connecting polygons together and making some adjustments.

That kind of lets you leverage some of the best parts of each method - there are a lot of panels of the car that you can generate really quickly by sweeping NURBS but then use sub-d to connect pieces together to get that kind of all-directional melted blending between all pieces.

You can do that with human faces as well, but it is even more suited for cars because there are kind of more natural large panel areas that are well suited for sweeping.


One other very general tip is that when doing this kind of surfacing in NURBS in many cases you need to imagine the "trims" in the original panels. Like when you come to a wheel well, don't try to build little surfaces hugging along each outline curves like you would with a poly modeler. Instead you want to build bigger surfaces that kind of extend through those areas, then trim holes and cut away areas.

That's a really key thing that lets you move faster and keep larger areas nice and smooth.

That takes some getting used to since trimming is so generally avoided in polygon modeling but similar to booleans it is a more fundamental frequently used thing in NURBS modeling.

- Michael

Hi Michael,

>>there really isn't any one single program that exists which contains every single possible 3D design and analysis tool combined within it.

I'll have to disagree with you there, when your talking high end cad packages (where you have to sell your first born to purchase) you are paying for just that, a swiss army knife of cad it knows all does all, in nurbs that is, but the difference is it's the one program but different modules depending in what field your in.
I'm talking engineering and industrial design sector, if your designing cars you make sure you get the styling module but if you have the money you can get it with the lot.

>>That's just a pretty normal process, I mean if you want to hammer in some nails use a hammer for that, not a screw driver or a drill press. Does that mean that a drill press is useless? No, not at all...

I agree here, but if you have all those tools in one toolbox you've got the lot ready and waiting to use for the task at hand and as I said it all comes down to, how much do you want to spend.

Cheers

Hi Danny,

> I'll have to disagree with you there, when your talking high
> end cad packages (where you have to sell your first born to
> purchase) you are paying for just that, a swiss army knife of
> cad it knows all does all, in nurbs that is, <....>

Those are definitely missing the "easy to use" aspect which I certainly view as an actual kind of technology and "tool" in itself. This aspect is often kind of pushed under the rug, but I think that is kind of a shame. In a certain sense it is kind of mutually exclusive with the "swiss army knife" type stuff.

I'm still not so sure that even the "highest" of the high end really has every single thing in it. I mean the fields are so vastly diverse, just off the top of my head:

Hydrostatic analysis for ship design.
Hull design tools
Computation fluid dynamics for airflow analysis
structural analysis
inverse kinematics for armature simulations
subdivision surface modeling
sound wave analysis for acoustical design
optical analysis for lens design
Thermal analysis for cooling systems
Building information management for architecture
Generative modeling for algorithmic architecture construction
Jewelry specific stuff
Automotive exterior "Class A" surface design
Shoe / last design
Apparel and clothing design, fabric unwrapping tools
Civil engineering / site stuff
Plant design / piping


Do you know of a program that has all of these tools simultaneously available in it?

I mean it is not always about technology itself, some areas need custom tools that just automate tasks that are things specific to a particular domain and not used for sort of more general consumer product type manufacturing...

Probably the closest thing would be Catia. But as far as I know it does not cover every single one of these areas at the top level of effectiveness. For example, does Catia have a jewelry design module that makes it easy to have a library of settings, stuff like that? I mean if it doesn't then it really is not the best tool for someone who is doing rings, even though it is a "high end" super expensive tool.

Another simple example kind of closer to home - do you know of any existing high end CAD tool which will allow you to export NURBS to polygon mesh data using multi-sided polygons instead of just triangles and quads?

- Michael

Hi Michael,

>>Those are definitely missing the "easy to use" aspect which I certainly view as an actual kind of technology and "tool" in itself.

Yes, they do have a steep learning curve, I guess that's why they hire specialized engineers to run these programs.

>>I'm still not so sure that even the "highest" of the high end really has every single thing in it. I mean the fields are so vastly diverse,...

Well I was talking about 'hard' engineering and industrial design including auto.
One particular program that does cater for all in these areas that I know of is Siemens NX (formally Unigraphics) and in relation to the areas that I mentioned it comes close with the bundles/modules they offer, plus third party plugins, plus in house programed specialty tools, which the software allows you to do via VB, C++ and Java.

>>Do you know of a program that has all of these tools simultaneously available in it?

Why would you ? Well, now that you put it that way, no, but you've got a mixture there of 'hard' engineering, architecture, civil engineering and specialized analytic tools which I wouldn't expect to be in a cad program but as a standalone tool.

>>do you know of any existing high end CAD tool which will allow you to export NURBS to polygon mesh data using multi-sided polygons instead of just triangles and quads?

Yes....................MoI :)

.