Interpolated Curve Issue

Hi Guys,

I’m having a bit of issue here, probably its just a small thing that I missed out (hopefully) but for some reason my set of points on attached image don’t really produce a smooth interpolated curve.
Any suggestion to solve this issue ?
ripple.dyn (14.9 KB)

Many thanks

Hi, you can try a NurbsCurve.ByPoints (points, closeCurve) instead. See also here for some basics:

Just change the degree to something larger than 1.
Here is quick example ( Ive sorted the points first to be shure that 'they are in the right order from the point in red.)

@Yna_Db Thanks, it resulted the same weird curve.

@Petar_Penchev1 Yep the Degree by default was 3 but still it act weird. My list of points has also sorted in correct order.

That is strange. You can see clearly from the example I’ve posted that evrything goes well. Please upload your script and sample rvt model to be able to investigate where the problem is.

@Petar_Penchev1 You can download the script from my first post, the revit file basically just a single model line. Many thanks

Hi There,

It looks like that the specific of the position of the points are causing the strange behavior of the Nurb node.
Here is my try on the topic. I’ve amended your script a little bit. Just to try. I’ve set up every second point to offset from the original curve on the normal vector to the curve. You can experiment with the number sliders to see how the nurb curve changes. Hope this helps you understand the nurb curve behavior.

MyTry.dyn (13.2 KB)

Thanks Petar,

I have just used your script and still it act weird in mine. Probably there’s a problem with my Dynamo. See below picture


As I said, Dynamo is working just fine. This is due to the nurb curve geometry behaviour. If there are a lot of points the nurb curve is not smooth. if you decreace the points (like on my screenshot - 20) the curve is smooth. The problem is there are a lot of points very close to each other and the curve can’t be smooth.
In the script I’ve uploaded you can try and see which is the gratest number of points which gives you smooth curve.

Ahh I see, I might need to find another solution using PolyCurve though as I’ll be using more than 50pts which doesn’t really work with NurbsCurve as you mentioned.
Thanks for helping Petar :slight_smile:


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This is just the visual representation. The curve is ok, only the displaying is not:


This was interesting. It is good to know the problem is only in the displaying.
Of course you can use polycurve fillet options if that suits to your purpose.

@viktor_kuzev thanks for clarifying this Viktor, didn’t expect that before. I tried with Grasshopper with the same workflow and all good.

@Petar_Penchev1 Thanks mate, guess I will down with NurbsCurve as the polycurve is quite heavy when I have too many points


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