Nurbs2IGES

This code allows one to convert a NURBS Surface to an IGES surface file for import into a CAD progra

Description

This code allows one to convert a NURBS Surface to an IGES surface file for import into a CAD program. Entity 128 is used and is the only entity type output. NURBS curves could be output with some modification. This code is rough but works for what I am doing.

Attached IGES format guidelines to help understand it. All the lines (in the *.igs file) on the right MUST line up or the file will not open up.

• Acknowledgements: This submission has inspired the following:; igesout, IGES Toolbox
• MATLAB release: MATLAB 7 (R14)
• Other requirements: NURBS toolkit

[Luigi Giaccari]

Nice Work!
A few question:
-Do you know how to create triangular NURBS patches?
-How to export multiple surfaces in the same file?

Thanks!

[kunal]

Hi, all

I am using NURBS Toolbox and IGES reader for MATLAB. The IGES reader is supposed to read IGES files from CAD softwares and extract geometric info from it. When i try to extract entities 126 and 128 (which correspond to NURBS Curves and surface). I am getting inconsistent results.

for example.

when extracting NURBS from a Cylinder IGS file from solidworks, I am getting no surface at all. When i use Rhino 3D i get a nurbs surface which looks like a cylinder but it's not Circular in shape like the IGES file.

I need to extract a proper NURBS surface that looks exactly like the IGS file

[Roland]

it happens that the end line delimiter (?) "G0000001" of the second line does not align with the other delimiters, than some CAD programs (like freeCAD) can not read the iges file. In this case, I just edit the iges file manually, but it would be good to make the output more robust.