Point on curve at distance from start

I want to get the point on a curve at a distance from start.
I Know I can use “Divide length”, and then pick the first item, but this is time-consuming and silly with long curves and short distances.
I just want ONE point.

U can use rhinocommon method:


FisrtPoitAtLength.gh (6.0 KB)

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Assuming you’re looking for a native Rhino tool…

If the curve is straight, you can use the From or Along osnap modifiers.
Start the command you want, move you mouse pointer over the Osnap toolbar, then press and hold Ctrl. The toolbar displays additional tools including From and Along.

SubCrv? use option copy and type in your length.

Fro native RH tool, you can work around by using Flow Along Curve command:

SubCrv with Copy=No and MarkEnds=Yes. Select one end of the curve and type the desired length. Points will be created at the start of the curve and at the requested length.

nice, i dont have “ends” on the old mac version…

Nice to see that SubCrv is improved in RH6

Thanks folks,

I failed to put this post in the GrassHopper category.
I don’t care too much about Rhino tools anymore.
Thanks for the C# component Radovan.
Let’s see if it goes faster than “Divide Length” + select first item…

you can use the method you already mentioned and create cluster

That’s not the point.
I want a component that goes faster

It looks like the “evaluate length” component (in curve analysis) will do what you are asking.

Drew

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Hi Drew,

Yeah, I overlooked this one indeed, but it still requires to calculate the ratio between the desires length and the total curve length.

It does speed my anemone loop a bit though : 2.1 sec instead of 9.4 sec.

Thanks !

yes exactly, divide create thousands of points

Extend curve with negative lengths + end points is an easy way to get points on both ends of the curve. Evaluate Length has an input to switch between normalised length and genuine length I think.

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DAMNED that’s right ! If I set “Normalize” to “False”, I can input the length value directly.
Here is the perfect example of an ill-named input : When you read “Length factor”, how can you interpret it otherwise than being a ratio of some sort ?

Interestingly, the “Evaluate length” component is faster if one goes through the trouble of inputing the length ratio then having it done automatically by changing the “Normalized” input to “False”.