Hello,

I am new to nurbs based modeling and am already interested in making a complex shape. Essentially I would like to know if there is a simple way to smooth 2 spheres and a plane. I have tried the blend tool and all by itself that doesn't seem to generate the results I need. I also have tried to use Network after building up some silhouette of the spheres but that didn't work either (and in some cases made some very bizarre shapes). Same with loft and sweep. I am wondering if perhaps the only way to build this will be to build it manually with curves?

Can someone take a stab at an easy way to smooth these 2 spheres? Keeping the smoothed surface tangential to the sphere surface and still have it be easy to modify in the future would be preferable.

Thanks,
Chris

Attached is a "demo" of what I am trying to achieve, but failing.

I redraw all your curves, becouse yours was not tangent, you can redraw mine to get result that you want or add onother to shape figure. Use my curves and make network, it's the easy way to make this shape. Also you can use sweep with scaling rail. There are couple another ways but with network is eyasy way)

Hi Chris, for using Network you need to have a particular arrangement to the curves you give it, they have to be unwrappable to a 2D grid pattern kind of similar to lines of latitude and longitude on a globe for example. If you have a set of curves that don't map to a regular grid then you'll get pretty weird results with it, because it will have some part of it forced to a grid anyway. Check out Andrei's curve structure for an example of how they would need to be arranged.

For using blend you would want to do something like this - draw in some lines and use Edit > Trim to cut the spheres so you have only 2 fragments like this:



Then selecting those edges and doing a Construct > Blend will build a connection piece like this:




But in general one thing to keep in mind is that the main strength of NURBS modeling is in construction of mechanical shapes using mostly 2D profile curves to do a lot of the work both as generator curves for doing extrusions, lofts, revolves, etc... and also using curves as cutting objects for boolean operations. Highly organic models that are not easy to describe with 2D curves tend to be better done in a sub-d modeling program rather than in a NURBS modeling program.

So in this case here with a kind of organic semi blobby shape you're kind of heading out of the territory where NURBS modeling is really best suited for.

Check out here for some general information for people who are new to NURBS modeling coming from a poly modeling background. These examples may help give you more of an idea of the kind of techniques that you would usually want to focus more on with NURBS modeling:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

- Michael

Hi Chris, or also a sort of more structured NURBS modeling approach using 2D curves might be to draw a 2D profile like this and then use revolve to make the 3D shape from it, rather than trying to build the 3D shape in little individual patch pieces. With NURBS modeling you usually want to make larger pieces of things from 2D curves, if you find yourself building little individual patches at a time that's sort of trying to do a polygon modeling approach and NURBS modeling works best with a much different more sort of "construction from 2D curves" type of approach.

Anywhere here's what a revolve would look like:





- Michael

Michael methods with blend and revolve are good but they do not match the long middle curve he drew on his example

Oops yeah I was looking more at the top view and kind of missed that part.

That kind of blobby form that is not very well defined by only 2D profile curves tends to be better done in an organic sub-d modeling program rather than in a NURBS modeling program.

- Michael

"""""""""Michael methods with blend and revolve are good but they do not match the long middle curve he drew on his example""""""""""""""

Well, nobodys example matches his curves because it cant be done. Even yours are redrawn to be different. It kindof depends on what he is really after as to what needs to change.

BurrMan
I do not aim to match it exactly just made it fast to show method. He can redraw it to meat his needs. I think it is possible to redraw it to match his example as close as posibble.

Yes, but there is no longer "sphere's..... Michael showed a simple revolve, which was his z zero profile. "2 spheres connected smoothly".

You showed a complex network That was none of the spheres and cant be.

""""""""He can redraw it to meat his needs.""""""""""

Yes. Agreed.

My little method :)

Andrei,
My post was not to mention that anything is "wrong" with what you did. It was well done. I wanted to point out to the OP where he missed it.

You pointed out that Michaels method missed the center profile (correct) but he got the other parts correct! Your method looked at the center profile, but "all the other parts were missed!"

It comes down to what is the outcome that he really was after, and that something has to change.

If he gets that part, then he should be on his way.....

Welcome aboard Chris:
all guys answered right to your question..i just wanna give you a general tip,being you a newbie
Please pay attention HOW to draw splines and keep them ALWAYS as clean as possible.
Take a look at your circles:points are not symmetric... :'( :'(
Avoid also to have a bunch of messy points in a little area like red arrow shows










M

BurrMan, no problem man, everything is ok)