Sorting the output points in pairs-drawing parallel members in Tekla

Hi everybody
I am new to GrassHopper and have inserted a Tekla component (seam type) into my model (steel bridge). it takes two points as input. the component should be repeated along divided curve (bridge line) multiple times. now my problems are:

1- I need to input points in pairs to the component. assuming the curve (bridge line) have been divided into “i” segments.
the input points must be as follow:
Input 1(P0, P1)
Input 2(P1, P2)
Input 3(P2, P3)
Input i(Pi-1, Pi)
how can I sort such pairs as inout?

2- how can I make the tekla component (or any grasshopper component) repeat itself for each input pair?
in the attachment is a screenshot of the situation.

the other question is that how can I draw multiple members (beam) with given distance and picking only two points in the project as the project line? it is neccesary for example in composite deck bridges. is these any other method other
than drawing each beam with beam component?

this should do the job of picking pairs.

basically you shift the list and use “Graft” and “Merge” in order to built the paired items.

Just the last branch of the tree you have to discard because it either wraps back to the first item due to shifting, or in case of “false” (W input on shift node) it will create only a single point and not a pair

I think “graft” is what you are missing, because that will apply the node to each branch(sub list) of your data tree: (16.6 KB)

also make sure you use “draw fancy wires” it will show if a list is flat or grafted


1 Like

Thank you very much
really helpful and exactly what I wanted to sort the pairs. have you any idea to make the component repeat itself for each input points? now it just runs once.

sorry, not sure what exactly is the issue here, as I don’t run TEKLA.

For usual grasshopper components, each branch will be treated as an individual processing iteration, so the way items are formatted after the merge node, should do exactly that!

*maybe you need to adapt the formatting of the other inputs of that node, so that it runs properly.
You might need the same number of branches for each input. depending on what the TEKLA node wants…