Data list order doesn't respect shift-connect order?

Grasshopper
1

Hi there … so i’m trying to construct a NURBS curve with 4 points.

I thought that when you connect multiple inputs with the shift key that the resulting list is ordered in the order you connect the inputs … this works fine for the first 3 points (i connect the first point then shift connect the second and then the third):

Screenshot 2022-06-25 at 19.19.22
Screenshot 2022-06-25 at 19.19.221316×940 14.9 KB

but when i connect the fourth point suddenly the order changes:

Screenshot 2022-06-25 at 19.19.42
Screenshot 2022-06-25 at 19.19.421356×848 18.4 KB

i’ve been trying everything i could think of but cannot figure out why this happens or how to get the points in the order i need to construct the curve i want successfully. I’ve always used the shift-connect in order so far for a variety of things and have never run into this. As far as i can remember the order you connect things is the order the list comes out of the output.

When i try this out on an empty patch it works like expected and the points stay in the order i connect them to the nurbs curve component vertices input, so something in my patch must be the issue. Unfortunately i can’t share the whole patch here but am surprised that this happens at all … i thought a point was a point so i don’t understand what causes this. The first and last points (0 and 3) are just end points of a line but the second and 3rd (2 and 3) are points from a surface evaluation, i then flatten the inputs of the NURBS curve component.

what am i missing ?

2

ok sorry everyone … talkin to myself here … i figured it out :rofl: :rofl:

so the issue was that i needed to flatten a component that was generating the last point, now it works.

Lesson learned, panels are super useful … and tree structures are complicated :blush:

3

Flattening a parameter that receives many different sources is tricky, as you discovered.
To be sure you can flatten each and every sources where they are, but this prevents you from having the original tree structure to do something elsewhere.

Best solution: use Merge component and flatten its inputs parameters if needed. (when in doubt and you know you want a simple list, just flatten its inputs).

1 Like
4

ah yes @maje90 just tried this out and it’s indeed a much better solution to keep the original structure and flatten at the merge inputs … i had never used the merge component before so i’ve learned sth valuable there :yum:

1 Like