Making a gill-openings structure just open on one side

Grasshopper
1

Hello! good afternoon, im working on a train station model and right now im doing the envelope of the structure. I decided to use a surface from rhino as a base and then use some graph mappers to make the structure open like some fish gills. I got the openings to a shape i like but now im trying to make the openings just open from one of the sides. On the image eloquently labelled ex. 1,

image
image546×634 58.4 KB

I show with orange lines how i have the openings right now on my structure, and with the red lines i try to portray how i want them to be, more closed. I tried baking the final surface i got and then getting the center from each segment and then rotating them, but that make the whole segment to rotate, making the lower edge surfaces to also rotate and make the structure not buildable (as seen on example 2)
image
image1018×621 61.6 KB

I now im trying to go back to solving this from grasshopper but using more graph maps, but its not working. I am now stuck and do not know what to do, does anyone have any tips or ideas on which componente would help me split structure in two parts so i can only open one of the sides?

ill attach both the .3dm and the .gh file
trainstationrotationhelp.3dm (633.3 KB)
trainstationrotationhelp.gh (14.0 KB)

2

try this
trainstationrotationhelp[fixed].gh (42.4 KB)

the logic is to multiply by the parameters returned by divide surface. i reparametrized the surface so those parameters should be from 0 to 1 as the surface goes from one side to the other. pass those values to a graph mapper to control the transition

image
image1871×735 207 KB

3

@Sebastián_Emiliano_H this is slightly improved version. i noticed that as you play with the graph mappers you had previously, the ends sometimes rotate, so i fixed that too - now the ends always stay on the edge of the surface.

[trainstationrotationhelpfixed[v2].gh (34.9 KB)