Hi Michael, the way Network works requires a fully regular grid layout, which means that all the curves can be flattened down into a 2D grid pattern.

It's kind of similar to how curved latitude and longitude lines on a globe can be mapped to a flat 2D map with horizontal and vertical lines for each of them.

If you have something like this curve in yellow here:



Then you can't have something that only crosses it by some partial amount like this other one here:




What will happen in your case above is that some of the pieces will be considered be excess portions hanging off the end of the regular network and will get trimmed off.

To make a network you need to have a more regular grid pattern to the curves, more like this:




The curves should be clearly separated into 2 different groups (like latitude and longitude), and each member of one group should cross over all the curves in the other direction.

> In addition to this, I´d like to know if there´s a
> function to weld curves together into a mesh?

You mean so that you could pull around intersection points? No, that's really trying to process things more like a polygon mesh modeler would work.

Really the strongest area of NURBS modeling is when you are generating shapes and cutting things from 2D profile curves rather than a big bunch of curves swooping all around in 3D.

Also if you do have some 3D curves, you generally want to make more broad and simple surfaces from them and use booleans and trimming to put in some kinds of cutout details, rather than trying to build surfaces directly around hole outlines.

Frequently I see people with a polygon modeling background try to build things in a more "patch by patch" method with building surfaces that hug around a hole, rather than the NURBS way which is to make a big broad piece and then cut it.

Do you have an image or drawing of the model you are trying to create? That may help me to give you some more specific tips, but if your model has a lot of freeform nature to it and is not easily described by 2D profile curves, that could very well put it in a category of things that are more suited for sub-d/poly modeling with its focus of tweaking 3D mesh points around, rather than the profile curve driven strategies that are the best fit for NURBS.

- Michael