Tangent at kink returns zero vector

I created two nurbs curves and I joined them in rhino, and then I closed them with the Connect Curves component (bulge = 0) in GH. When I call from a scripting component to the Curve.TangentAt(t) method when t is the last kink, it returns a zero vector. Is it a bug?

TangentAtKinkBug.gh (7.5 KB)

Any thoughts?

if you bulge = blending factor is 0 then it sounds like your creating a singular blend curve (or a curve with inner singularities), which obviously returns singular tangents & normals. That’s what I would guess…

Thank you for your answer. Can you elaborate this please? I don’t understand in what circumstance it makes sense to return a null tangent. And even if it does exist, it seems too deep for the developer or user to have to worry about this, doesn’t it?

Hi @Dani_Abalde,

The line segment, which is actually a degree=5 NURBS curve, has stacked control points.

– Dale