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curve bridge crossing a third curve

I need to bridge the blue curves (Curve_1 and Curve_2) and hope the bridge to cross the green Curve_A.
Is there any easy way to do the job? Thanks!

Re: curve bridge crossing a third curve

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Did you try to use a spline?

you can create a point on the curve (use intersection point between a datum an the curve)

Then create a spline throug the points.

You can make the start point and end point tangent or curvature to the curves (also you are able to change the magnitudes)

Ruud van den Brand
Pre-sales NX CAD
cards PLM Solutions

Re: curve bridge crossing a third curve


Hi @ruud_vandenbrand  Thanks!


I just need the curve bridge to cross the third curve, but not an arbitrary point on the third curve.


If an arbitrary point on the third curve is forced on the curve bridge, the bridge is possible to be distorted.

Re: curve bridge crossing a third curve

Siemens Phenom Siemens Phenom
Siemens Phenom

Hi Surfactant,


I assume that you want to create a bridge curve from A to B just touching a point somewhere on the green curve/line without actually controlling where, but to let the system use the optimize the touching point. Using Spline you will have to define a point either prior to creating the spline or while creating the spline (the second point of the spline will be a point along the green line).This will be the simpler way but maybe not be what you want....


The I think you're after is by letting the system define the actual optimized point depending on the constaints at the start and end. Should this be what you want you need to create supporting geometry like in the picture. The blue surfaces are an extrude in the green line direction. The Green surface is a transition surface with whatever constraints of your liking to the blue surfaces. The surface is also run through the green line to ensure the downstream requirement of intersection/point touch. With this support geometry you are now able to do a Bridge Curve using the dark blue curves as Start Object and End Object. By using the Green surface a s Constraint Face you will ensure the Bridge Curve to touch the Green Line in the optimal point.


I hope this helps.



Best Regards


Re: curve bridge crossing a third curve

Siemens Phenom Siemens Phenom
Siemens Phenom



There are several analysis tools in NX that you could use; like deviation.

Another possibility would be a distance measurement feature. You could even use a goal seek to find the correct inputs then. In the movie I just show you the manual trick.



1. hold the ALT key down while dragging a handle to turn off the smart rounding

2. Use menu / preferences / modeling / update settings to make the down stream features update live while you edit without rollback.


Regards, **bleep**

(view in My Videos)


Re: curve bridge crossing a third curve


Hi @Sandman   Thanks for sharing the solution based on "Constraint Faces"! But I try to create the bridge curve between two curves only to prepare for constructing the bridge surface. And in the example I used lines only for illustration, and in the real situation they may be 3D curves.


Hi @DickBaardse   Thanks for sharing the very useful trick! The solution has one issue. When the size of the model changes later, the bridge would fail to cross the third curve in an unnoticeable way.