PolyNurbs 1.0 - Released

19 votes
Date Updated: 

PolyNurbs is a tool to convert nurbs objects to quad poly.


A lot of us want to use nurbs or spline to make our quad meshes. I have tried a lot of solutions, scripts, surface modifier, turn to poly and detriangulate... but no one works as we want.

With PolyNurbs you can:

  • Convert a nurbs lattice to poly object (so you can turn on subD in your poly, and they will have similar form).
  • Convert poly object to nurbs lattice (inverse operation. Note: only patch-like meshes can be converted, due to nurbs maths)
  • Convert a nurbs object to poly object, fitting points in their surface (with SubD activated, this poly will no fit your nurbs, due to hull convexity property)
  • Additionally, it can convert spline to nurbs, and nurbs to spline.

Version Requirement: 
3ds Max 2008 - 2012
Video URL: 


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Ruddy's picture

Just out of curiosity, could

Just out of curiosity, could this script ever be turned into a Modifier that could create the poly surface in a live/active way?

herbap's picture

thanks for reply... but...

try with new and clean mesh. checked with graphite's "non-quad" tool :) this mesh only has quads

i get this error,
-- Type error : Selection index must be number or array or name, got: undefined

graphic design and animation

luisllamas's picture

Probably because you're using

Probably because you're using a mesh that can not be converted.
As it says in the instructions "only patch-like meshes can be converted,". That means 100% quad mesh, forming a rectangle of NxM quads.
This is due to the way in which Nurbs maths works, and is unavoidable.
The error message is because exception handling is not implemented. Sorry about this! Maybe I fix it in a small update, when I have some time.

herbap's picture

runtime error when converting mesh to nurbs


looks like great script but try convert mesh model to nurbs (746 vert, 744 poly) and get this error

--runtime error: epoly vertex index out of range: < 1 or > 746:747

how can i solve this?


20130226_122004.png 5.72 KB

graphic design and animation

tommym's picture

Nurb swirls


Is there a way to animate the nurbs surface as curves change position. I have not had any luck doing this. For example by rotating the 2 straight edges that you show and the surface between will follow like twisting but giving smooth surface in between.



City Slicker's picture

Awesome tool!

High fives to Luis for putting the time in to make this plugin. I was struggling to control nurb conversion until I used this.

barigazy's picture

Very nice script you have

Very nice script you have here.
With this tool you can do amazing forms in architecture,
car design and other area. +10 for you.


clueme's picture


Thank you. it's my favorite script ^_^

npiovan's picture

Everything is working now

Everything is working now thanks

luisllamas's picture

npivan, you are still having

npivan, you are still having the same problem?

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