Hi Stefan, branching structures that are all smooth and melty at their junctures tend to be difficult to build with NURBS modeling. Structures like that are usually a lot easier to build with sub-d modeling instead.

You can sometimes use the technique shown here to do branches though:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4388.55

But my main advice would be not to build that kind of thing out of NURBS geometry, sub-d modeling is better suited for that kind of shape.

NURBS modeling is strong when much of your model is defined by 2D profile curves and has distinct cuts in it. Your model there is not a form like that at all, it's more organic blobby with branches, that's where sub-d modeling is strong.

- Michael

Thank you very much for your explanation Michael,

yes, i should better try to do this shape in sub-d. However, prior reading your reply i tried also Andrei's example which worked nicely, but imho did not matched the tail right, like getting very thin at the end. So i tried to model the profiles and the curves in MoI again and tried the "Cover Surface" function out in an old copy of ViaCAD. My humble approach one can see here, how the tail (were it's getting thinner at the end) should imho look like. After that i imported the cover surface and mirrored it in MoI and made also a solid out of it. But i'm not sure if this would represent a good smooth surface model...

Best regards
Stefan

Hi Stefan, yeah it's generally difficult to get a high level of smoothness with NURBS when building things in separate patches like this. Usually you have to do a blend or fillet to make a smooth connection, just constructing things adjacent to one another they won't be smooth. That's pretty different than sub-d modeling, where everything that's connected together in the sub-d control cage will get smoothed out.

Your model is fairly close to being smooth, you can more easily see the small creases between patches if you export to a pretty high density polygon mesh and turn on some reflective lighting (called "metallic lighting" in MoI under Options > View > Lighting options):



You could probably improve the smoothness of the model in those areas though by cutting away a little bit of area and then putting in blends, same technique like Andrei shows in the video above in this same thread.

But really both branching and smoothing at the same time just tends to fit a sub-d modeling toolset better.

- Michael

Futagoza,
this is how it can be don perfectly smooth in one surface piece.
I made it with loft (Loose, exact).

I tried to make the same thing with sweep but found it boring, can not get good result for 5 minutes and leave this method.. I like here Loft more.



I attached project file, you can download it and tweek it for your needs)

Loft the return! :)

Sometimes it can definitely help to build an extended shape like Andrei shows above and then slice off some extra area of it.

But that can also just push some problems further down the road if you want to continue to build new pieces onto the model as well, if what Stefan showed was only one portion of the whole smooth blobby model and not actually the final full shape.

The way Stefan sketched out the shape for that very first screenshot by having a sort of outline hull of your shape is just not a good way to approach NURBS modeling for making big smooth surfaces, that kind of "non-rectangular topology outline hull" really matches the way sub-d modeling works.

For NURBS modeling it's usually best to make smooth surfaces out of one single big surface which can then be trimmed to give more possibilities (what Andrei shows above is a good example). But the more that your model becomes a large and complex all smooth skin it generally becomes more and more of a candidate for sub-d modeling techniques instead.

NURBS modeling usually works well when there is more of a kind of "component" nature to the model, and you have fillets connecting different component pieces together.

When you are trying to do one big complex all smooth melty looking skin with not very distinguishable components in different areas, that just does not match the NURBS workflow very well.

- Michael

Pillou, Yep)) I'll be back)))

Michael,
>if what Stefan showed was only one portion of the whole smooth blobby model and not actually the final full shape.

I think he can show the full model, and I can try to make it)

Nice techniques Andrei, thanks for sharing.

Marc

Hi Michael and Andrei,

thanks again for explaining and showing a Loft solution again, much appreciated!

@Andrei, actually the first picture in this thread of the wires, was the whole model, which the person made, to show if it's possible to model such a shape with NURBS. If i remember correctly this guy was a SCI-Fi enthusiast and wanted probably later add details to this model...

Best regards
Stefan

Deep Space Force are ready!!!

May the force be with you!



Adding a details is very simple and fun part. That is why I love moi)

Project attached.

Marc, Stefan
You are wellocme guys)

I think practically any type of hard surface can be made in moi. May be it's not the usual way how Nurbs work, but it works))) So why not to use it)) May be it's time to look at nurbs from another point of view)? What If I don't want to use Sub-D, I want to use MOI :D)))))

Cool Andrei!

Thanks again very much!

(yes, i also prefer to use MoI, instead of sub-d... ;-))

Best regards
Stefan

And something like this ? Funny a different function by step! :)

Hi Stefan,

> to show if it's possible to model such a shape with NURBS.

Basically it's not easy to do it if you only use their specific topology layout, but it's possible to get the same kind of shape using a different kind of topology like Andrei shows.

If the person only wants to work with that particular style of drawing by putting in a kind of direct patch by patch hull, sub-d modeling just tends to work more like that kind of method so it could be pretty likely that sub-d modeling might be a better fit for their particular process of working.

NURBS modeling just does not work very well if you try to do things that are supposed to be broad smooth areas only out of little separate sub patch pieces, it's usually better for big smooth areas to be built out of one big surface, and a single NURBS surface needs to have a regular row/column layout to it.

- Michael