Grasshopper

algorithmic modeling for Rhino

# How to split an ellipse??

How can I trim an ellipse like in the picture, if there isn't any surface outside of it?

I have one ellipse and two lines with end points. I want to trim the outer part of the lines, that I have just a quarter of an ellipse.

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### Replies to This Discussion

thanks daniel, thats the second time today :) u re great man

buy the way, I tried your description but I'm little bit confused, can u maybe explain me the logic of this way please

Shatter comp. need two parameters to split a closed curve. So, if you have points in the curve (wich are where you want make the split), u can know wich parameter correspond each pt on the curve with Curve Closests Points.
You need n(number of curves)-branches, one branch with each curve and one branch with the 2pts of each curve.
A value parameter of a curve is like the position of a virtual pt, where 0 = start and curve.lenght = end, or if the curve is reparametrized, 0 = start, 1 = end.
U get it?

oh ok now i understand and what did you connect with the index in the list comp. ?

Shatter comp. returns 2 curves in each branch (the part that you need and the part that you want delete), so you need select one of then in the list of each branch. The index should be 0 or 1.
In GH, the objects are not deleted as other software, instead, select the objects that you want using lists.

i dont wanna waste your time with silly questions but its not working.

so, i have three points a,b,c

a and b are on the ellipse

c is the center point of the ellipse and also the end point of a and b

1) i connected the ellipse with the closest comp. as curve

2) i put a and b as 2pt branch and i also tried it with abc together

3) i did the same thing like u and put 0 for the index, also i tried 1

but nothing changed. do i have to do something else after the list comp?

Check if you are doing something bad.

Attachments:

As you can see, nothing is changing, i dont understand it, is there anything that i do wrong?