Failed to link OpenNURBS library

I got OpenNURBS source code(version 6.x) from github and compiled it by visual studio successfully.
Then I tried to write a simple program to generate a 3dm file as example_write.cpp in source code did.
It failed with error LNK2001 unresolved external symbol “public: static class ON_Color const ON_Color::UnsetColor” (?UnsetColor@ON_Color@@2V1@B)
and other linking errors

I had added opennurbs_public.lib into Project → Properties → Linker → Input → Additional Dependencies

Can anyone help me?

The code is following:

#include <opennurbs_public.h>

int main()
    const wchar_t* filename;
    filename = L"curve.3dm";
    ONX_Model model;

    model.AddDefaultLayer(L"Default layer", ON_Color::UnsetColor);
    const int curve_layer = model.AddLayer(L"curve", ON_Color::Gray230);

    ON_NurbsCurve* curve = new ON_NurbsCurve(3, false, 4, 4);
    curve->SetCV(0, ON_3dPoint(-10, 0, 0));
    curve->SetCV(0, ON_3dPoint(-6, 8, 0));
    curve->SetCV(0, ON_3dPoint(8, 6, 0));
    curve->SetCV(0, ON_3dPoint(10, 0, 0));

    curve->SetKnot(0, 0.0);
    curve->SetKnot(1, 0.0);
    curve->SetKnot(2, 0.0);
    curve->SetKnot(3, 1.0);
    curve->SetKnot(4, 2.0);
    curve->SetKnot(5, 3.0);
    curve->SetKnot(6, 3.0);
    curve->SetKnot(7, 3.0);

    ON_3dmObjectAttributes* attributes = new ON_3dmObjectAttributes();
    attributes->m_layer_index = curve_layer;
    attributes->m_name = L"my curve";

    model.AddManagedModelGeometryComponent(curve, attributes);


    return 0;

Hi @Hotege,

Where did you get the source from? Perhaps you should try getting it from here:

— Dale

@dale I exactly got source from mcneel/opennurbs on github.

Hi @Hotege,

The README in the openNURBS repo has some information on using openNURBS. There are also several “example” projects that come with the toolkit you can use a a guide for integrating openNURBS.

Do these help?

– Dale