Split a Curve in segments as same as Curve.SplitByPoints dynamo node

[MiguelGT17]

How is that dynamo provides a tool that split a Nurbspline curve into small segments but Revit API does not?

Am I wrong or do there exist some workarounds using revit API. The recommendations say it will be better if we create small segments of nurbspline instead of splitting the whole path. I do not agree as placing small nurbspline ends up with a different curve shape as you can see below:

red: drawing nurbspline  at small steps

dark: drawing nurbsplin interpolating between the whole points

Thanks in advances dear community,

Miguel G.

[jeremy_tammik · Accepted solution]

Dear Miguel,

Dynamo is entirely open source, so you can easily explore its inner workings yourself and see exactly how it achieves what it does.

That said, the Revit API does in fact provide the Tesselate method for all kinds of curves that does exactly what you are asking for:

https://www.revitapidocs.com/2022/f95f3199-3251-c708-c5a3-a0e9ef95ecfa.htm

Cheers,

Jeremy

[RPTHOMAS108 · Accepted solution]

Splines don't divide evenly the approach I used for splines on a plane was to:

1) Measure the length of the spline

2) Construct a circle of radius: Length/Divisions

3) Place circle at end of spline

4) Find intersection between circle and spline

5) Create circle at that point

6) Find intersections between circle and spline (you get two intersection)**.

6) One will have a greater curve parameter than the other*.

7) Move circle to that point.

Repeat 6 and 7 until end encountered (single intersection for bound curve). 

* When you use Curve.Intersect(Curve, ResultArray). I believe the U and V of IntersectionResult.UVPoint represents the parameter of the intersection along each curve. Order of UV will depend on which curve is passed as the argument to the function.

** The main issue with this approach is if the division circle radius is so large or the curve so complex within the circle that the radius of the circle strikes the spline in a way that isn't a segment length from the last point. I think for that reason I tended to first split the spline up into a polyline ensuring the segment size was quite small. Then if I needed less segments I would interpolate between the two points of the polyline segment closest to the curve parameter for each division.

[MiguelGT17]

Dear Jeremy, thank you for the prompt response

Thats a good point although I can not control the number of points that Tessellate works with. Regarding the following chapter from the building coder, I will be testing Evaluate() to make this workout.

https://thebuildingcoder.typepad.com/blog/2013/11/placing-equidistant-points-along-a-curve.html

[MiguelGT17]

Thanks for the Guidance Thomas, I'll be testing those tips as well to get this task done.

Cheers

[bobythe_builder]

any update on this @MiguelGT17 ? I'm stuck in a similar situation :(. Would appreciate your input on what workflow worked for you better. Thanks in advance.