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SystemofaDown
12-06-2006, 10:08 PM
Do you guys know if C4D will ever have a Nurbs toolset. Not as comlpex as rhino but have simple commands. Sometimes modeling something simple can take ours with poly modeling when it will take a couple of minutes with nurbs. 3ds and maya have them, why cant we? :)

soccerrprp
12-06-2006, 10:33 PM
I've read a little about "NURBS" and since i've never used it, I don't miss it. But, could someone please explain the advantages of them? And if they're so great, why doesn't C4D have them? I'm assuming that what C4D has is enough to simulate or overcome the absence of NURBS, correct?

Also, what could one do quickly with NURBS that would take considerably longer without?

Thanks all!

Richard

s66
12-06-2006, 11:03 PM
Nurbs or Non Uniform Bicubic Splines are used primarily for CAD CAM application as it is a truly resolution independent way of defining surfaces. This is great when you need to design machinery with high tolerances. Having said that, its not used much in the visual effects industry as the above advantages are seldom required and the disadvantages are many:

1. Everything must more or less resolve to "quads"

2. Entirely different texturing techniques required

3. Continuity issues can arise when stitching nurbs patches together

4. Must understand how Nurbs are "tesselated" at rendertime to avoid artifacts.

5. Discourages "design as you go" approach to modeling that poly modeling encourages due to "dead ends" (non continous surfaces).

6. Difficult to create local high and low poly regions in the same model as every isoparm must meet one another (unless you are trimming or filleting in which case you get continuity issues i.e. you may see seems at rendertime).

7. No vertex maps since there are no "vertices" as such. (Instead there are control verts)

8. If you move a control vertex on a nurbs, you have to know what order equation the curve/surface is to know how it affects the surface.

9. Nobody in the game industry uses them.

10. Very few people in the VFX industry use them except old Maya folk.

That's just off the top of my head. I'm sure there are many more disadvantages to using Nurbs. The reason I know is because I used Nurbs a lot when that was the only paradigm in the VFX industry and I pull a lot of hair out of my head.

-Sadato

soccerrprp
12-06-2006, 11:50 PM
Thanks s66. I don't feel that i'm missing anything. My conscience is clear and at rest with (or without) NURBS. :D

Per-Anders
12-07-2006, 12:08 AM
If you want to use nurbs you can play around with MOI which is currently free during it's beta http://www.moi3d.com/

AdamT
12-07-2006, 05:24 AM
s66 covered most of the negatives. :) On the positive side:

*they allow for more precise modeling;
*they offer better chamfers and fillets;
*they provide cleaner booleans.

Cinema's pseudo NURBS mimic some traditional NURBS tools, but there are also some omissions, such as two-rail sweeps and patch modeling.

moka.studio
12-07-2006, 01:12 PM
If you want to use nurbs you can play around with MOI which is currently free during it's beta http://www.moi3d.com/

thanks for the link , this is actually a really nice little app!

Neil V
12-07-2006, 02:05 PM
Doesn't it stand for Non Uniform Rotational B-Splines?

Nurbs or Non Uniform Bicubic Splines
-Sadato

ThirdEye
12-07-2006, 02:10 PM
Doesn't it stand for Non Uniform Rotational B-Splines?

rational, not rotational

Neil V
12-07-2006, 02:35 PM
I always thought it was rotational. Ah, well. You ive and learn, eh?

rational, not rotational

Jeff Warden
12-07-2006, 03:16 PM
Nurbs or Non Uniform Bicubic Splines are used primarily for CAD CAM application as it is a truly resolution independent way of defining surfaces. This is great when you need to design machinery with high tolerances. Having said that, its not used much in the visual effects industry as the above advantages are seldom required and the disadvantages are many:

-Sadato

I agree with your assessment. I've used Rhino on a daily basis since it was first introduced. I use it for designing products, and for that it's great, as it shares data with Pro-E and SolidWorks nicely, which are the programs engineers generally use to make molds for the products I design. You can make any object in Rhino, but the learning curve is steep. Meshing Rhino models for export to C4D is a pain in the butt.

I'm just getting into modeling with Cinema, and I must say your comment #5 about "design as you go" is spot on; with Cinema it's really easy to push and pull and squash and finesse your way to a nice shape, unlike Rhino which demands more from the user imho. With Rhino you need to know more about where you want to end up before starting your model. That's a bit of a pain, but not nearly the level of punishment you would be suffering if you had to design a sophisticated object natively in SolidWorks or other engineering-based apps.

So Rhino is the standard bearer (in my opinion) for nurbs based modeling if you want to manufacture or build the thing you're modeling. If you want still images or animation C4D is a better choice because of the many issues Sadato raised.

acmepixel
12-07-2006, 06:41 PM
If you are looking for spline patch modeling in c4D, there's a nice plugin that I use,;

Spline Patch

http://www.heyne-multimedia.de/c4dplugin/
http://www.heyne-multimedia.de/c4dplugin/splinepatch/splinepatch_en.html

It's a great addition to the c4d toolset and for building hard curving shapes like cars and boats.

capin
12-07-2006, 08:20 PM
Also, what could one do quickly with NURBS that would take considerably longer without?


Hi

this is very simple example modeled in Alias Studio Tools.
With nurbs its 5 mins including rendering.
In polygon modeling software like Cinema it can take hours. Depending on the precision u want to achieve. But even if you are willing to model this with polygons, dont even think about changing the diameter of any of those cylinders after...
For this kind of modeling its even better to use solid modeler. Its much faster than even nurbs (surface) modelers.

cheers
jan

s66
12-07-2006, 10:37 PM
Have stated all the negatives, let me say that for certain non deforming forms, nurbs are wonderful and once you get the hang of it, down right addictive. I use Rhino myself. Also note that converting a nurbs model with no discontinuities into a sub-D model is fairly trivial since a continuous nurbs surface consists of quads. I was kind of surprised that one of the modelers for the Matrix Revolutions used Modo to model intricate inorganic (ie machinery) forms. I know Renderman handles nurbs well, I wonder if there are continuity/precision issues when shooting the close ups. I love the way XSI handles nurbs, esp patches. However they seem to have all but stopped developing that part of the app. I could never justify the cost of Alias Studio Tools but it seems to be top dog among industrial designers. I think that dude on American Chopper uses Alias Sketch. Looks really cool but may be too rich for my blood.

-Sadato

Darter
12-07-2006, 10:57 PM
this is very simple example modeled in Alias Studio Tools.
With nurbs its 5 mins including rendering.
In polygon modeling software like Cinema it can take hours. Depending on the precision u want to achieve. But even if you are willing to model this with polygons, dont even think about changing the diameter of any of those cylinders after...
For this kind of modeling its even better to use solid modeler. Its much faster than even nurbs (surface) modelers.
This might be of interest:
http://www.3d-meier.de/tut9/Seite0.html

Bullit
12-07-2006, 11:11 PM
If Top dog meaning is in most complexe industries then it is ICEM Surf, then cames Studiotools.

s66
12-07-2006, 11:35 PM
I had never heard of ICEM - Surf so I went to their web site and it looks intriguing... so how much is this big bad boy?

-Sadato

AdamT
12-08-2006, 03:31 AM
I wonder if T-Splines are going to cause a slight resurgence in NURBS modeling? I've downloaded the beta Rhino plugin but haven't had a chance to check it out yet.

moka.studio
12-08-2006, 07:10 AM
This might be of interest:
http://www.3d-meier.de/tut9/Seite0.html

this illustrates perfectly how difficult it is to try to create blends in a polygonal model, which would be a simple click function in a nurbs modeller

Darter
12-08-2006, 09:25 AM
This is true.

Jeff Warden
12-08-2006, 01:05 PM
this illustrates perfectly how difficult it is to try to create blends in a polygonal model, which would be a simple click function in a nurbs modeller

Egad! I'm new to Cinema modeling, so when I saw the pics of this laborious creation of simple filleted blends I was surprised.

I like the way booleans work in C4D, i.e. the way you can resize things and have the boolean update automatically, and re-ordering the boolean hierarchy is pretty sweet too. Being able to easily blend the intersections of these objects would be nice. By "easily" I mean a few clicks, similar to the way rounding off a cube primitive works. Guess I have some homework to do.

TwinSnakes
12-08-2006, 02:14 PM
If you want to use nurbs you can play around with MOI which is currently free during it's beta http://www.moi3d.com/

I just saw a video of it. Looks pretty sweet, nurbs are nice.

But does it have the same export hurdles that Rhino does? ( I havent played with it so I dont know)

robodesign
12-08-2006, 05:44 PM
Hi

this is very simple example modeled in Alias Studio Tools.
With nurbs its 5 mins including rendering.
In polygon modeling software like Cinema it can take hours. Depending on the precision u want to achieve. But even if you are willing to model this with polygons, dont even think about changing the diameter of any of those cylinders after...
For this kind of modeling its even better to use solid modeler. Its much faster than even nurbs (surface) modelers.

cheers
jan

I have to disagree with your statements, at least partially.

Imediately I saw your attached image and your assumptions... I started modelling a very similar object in Silo [my favourite tool for modelling]. I finished it in 8 minutes and I'm not a guru in 3D modelling [or... at least I do not consider myself as one]. I assume a guru would model that even faster.

I can't say sure if in C4D it can be modelled faster or not, but... generally speaking... in C4D you got the same modelling technique as in Silo. Who knows, maybe you can be faster with C4D if you are a guru in it. I don't like the GUI for modelling.

http://www.robodesign.ro/_gunoaie/silo-modelling-test.jpg

P.S. Just 8 minutes. :)

AdamT
12-08-2006, 10:25 PM
That's a good effort, robodesign, but you can see that the main cylinder is still pretty lumpy. This is also a fairly basic example. It can get much trickier.

Glyptic
12-09-2006, 10:18 AM
I wonder if T-Splines are going to cause a slight resurgence in NURBS modeling? I've downloaded the beta Rhino plugin but haven't had a chance to check it out yet.

Hi Adam,
I just loaded Tsplines into the Nov 15 Rhino V4 Beta. Tspines adds a very nice modeling/deforming capability to Rhino's NURBS surfaces. Look at the vids on their sight.

As for exporting a mesh out of Rhino, Select>Export Selcted>select your desired format, click to Advanced settings and put in (top to bottom), 0, 0, .01, .2, .001, 0. Click Refine and Pack Textures. It might be dense, but it should be smoothe. Which is one of the main reasons to use NURBS.

I would love to see real NURBS in Cinema, but Tsplines could take some wind out of that desire.

robodesign
12-09-2006, 12:46 PM
That's a good effort, robodesign, but you can see that the main cylinder is still pretty lumpy. This is also a fairly basic example. It can get much trickier.

Thank you. If you refer that the edges of the main cylinder are too smooth, yes - I agree... But that depends on the number of extrudes.

And yeah, it was a basic example, but even things more complex like:
http://www.3d-meier.de/tut9/Bilder/Bild27.gif http://www.3d-meier.de/tut9/Bilder/Start.jpg

..... still shouldn't take hours.

One thing I need to say though.... If you are targeting to model strictly engineering stuff, pipes and the-like... then Rhino and any other application up for this, would be better than modelling with Subd. Still, for occasional stuff, you can do it in the poly-way ;).

vid2k2
12-09-2006, 02:57 PM
If I'm not mistaken, the examples you show were done in C4D a while back.

http://www.3d-meier.de/tut9/Seite0.html

Using the files he shows, you can use the fillets and extrude edges
to complete the objects.

Other than that, the AMA chamfer maker plug is a much needed addition to the tools.

AdamT
12-09-2006, 03:00 PM
No doubt it's possible to do excellent mechanical modeling with polys, and to do excellent organic modeling with NURBS; it's just a lot more efficient to do it the other way around.

capin
12-11-2006, 06:19 PM
If you refer that the edges of the main cylinder are too smooth, yes - I agree

P.S. Just 8 minutes. :)

Marius
Please dont get me wrong, Im a big Cinema fan, and i spent a few years trying to do industrial design with it, so i perfectly know how to do blends ,meier links and all that stuff. The thing is that its just not worthy.
You modeled those intersections in 8 minutes. They look sort of OK. But here is the point. You will have to spend another hour to make it look really corect!
I dont know what experience u have with nurbs and solid modelers. Doesnt seems much since u even tried to match nurbs intersections with 8 minut polygon job.
Take a closer look.

Jeff
What u described and wished for cinema booleans is the way solid modelers work. Its so cool. U union two cylinders, select edge, type in the radius: fillet is there. Deside to change diameter of one cylinder? no problem, fillet follows and updates.
Download the demo of Cobalt and try it

The great thing would be if Cinema had integrated Parasolid or Acis modeling kernel so u could use all three ways of modeling!

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