Hi everyone,
In Rhino, the Intersect command correctly finds intersection points between two curves.
In Grasshopper, however, the Curve | Curve component returns no results and sometimes throws “Object reference not set to an instance of an object.”
I tried projecting both curves onto the same plane, but the issue persists.
Is this a bug, or do I need to handle tolerance/data differently?
unnamed1.gh (11.6 KB)
Thank you for the suggestion. I understand that baking the curves into Rhino and then reassigning them in Grasshopper does solve the problem. However, I am more interested in understanding the technical reason behind this behavior: why does the Curve|Curve component fail to find intersections when using the original Grasshopper‑generated curves, but succeeds once they are baked as Rhino native geometry?
Thanku for sharing! I’ve also found that reconstructing or baking the curves into Rhino allows the Curve|Curve component to detect intersections correctly. However, I’m more interested in understanding the technical reason behind this behavior: why do the original Grasshopper-generated curves fail to produce intersections? Could it be related to curve parameterization, tolerance settings, or the way geometry is represented internally in Grasshopper? If you have any insights into this, I’d really appreciate a brief explanation—I’d like to better understand the mechanism behind it.
Could be a tolerance issue. How did you create the curves?
Thanks Martin.
I initially suspected tolerance too, but increasing the Rhino model tolerance didn’t help—still no intersection found.
How did you create the curves?
I think the line is not the problem.
but the degree 2 curve is. for some reason it is not pointdeformable as well.
would be great to have an explenation from McNeel.
curveProblem_jvs.gh (11.5 KB)
Interestingly the intersection works fine when a new degree 2 nurbs curve is created with the control points of the failing curve.
My Rhino on Mac crashes when I try to open your file. It opens with locked solver, but as soon as i unlock the crash happens. Your curves are cursed.
crash
YES XD my bad
This is a parameter space curve (UV Curve).
Yes, I hope McNeel can explain this.
How did you create the curve?
