Converting a polygon model to NURBS

I’m new here and not particularly highly experienced in modellling.
I have quite a large polygon model and wish to convert it to a NURBS model for further modelling.
The model has apporimately 60.000 polygons.
Is there any way of getting a decent conversion, and not just a surface conversion, with standard Rhino commands?
If not is there a service available for perfoming such a conversion without having to pay the price of an add-on? Since I’m not sure if I’ll ever need this add-on again.

thanks for any help

It isn’t easy or automatic. See for some ideas.

Hi Margaret,

thanks for the link, many of the listed add-ons I have already considered.
However due to the possibility of a one off conversion, the cost of some of these add-ons are daunting, and I am wiery of the capabilities of a couple of the cheaper stand alone programs due to the number of polygons in my model.

When you say “it isn`t easy” do you mean as in time consumption or from a “modelling skills” point of view?
I didn’t expect it to be a click of a button (although this is a nice thought) and am prepared to invest time as necessary.


Yes, it isn’t easy means Rhino is not designed for reverse engineering tasks, so it’s a time consuming process with no reall dedicated tools, but it isn’t impossible. I guess it all depends of the level of accuracy you’re looking for. Here’s a good tutorial that I think will help,

Otherwise some of the plugins have a demo that might work for you if it’s a one time job.

Kind regards,

  • vanessa

Ok thanks for the link, I’ll take a look.
I don’t really need any large accuarcy, just the shape and proportions should still fit.
I’ll see if I can get a demo add-on and try my hand at converting.

Okay… if it’s the overall shape then I think the tutorial and Rhino vanilla should do it. FYI, I think the tutorial was made for V4, but you should still be able to follow along without too much trouble.


  • vane