# Select multiple surface after split

script4.gh (18.7 KB)

I got the split surfaces from a surface.
I want to select the some surface like picture attached.
But im missing the way to do that.
Does anyone know how to do that?
Best, Keisuke

Hi,

Selecting some specific items among a data tree is not really the way Grasshopper is supposed to work. You can define an exhaustive list of items/paths to keep but if you change the number of divisions, everything has to be done again.

Iâ€™d suggest dividing the surfaces in two steps. First along one diagonal (blue lines), then sort those surfaces in order, then divide them again by the other lines. It is then easier to extract some stripes. I used `Sub List` but a lot of options exist.

script4.gh (22.1 KB)

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Thank you for your previous response. I have a couple of questions regarding your instructions.

Firstly, I understand how to proceed with your guide, but I am unsure about why certain components need to be included, specifically the ones highlighted in this image:

[insert image here]

Could you please explain the reasoning behind including these components?

Secondly, I am unsure about what the â€śtrim treeâ€ť function does. I have read some articles about it, but I am still a bit confused. Could you explain it to me in simpler terms?

Thank you,
Keisuke

just as a principle suggestion, without having looked into the .gh

the â€śselect/delete after splitâ€ť problem, can be avoided by using bool-type operations.

â€śtrim solidâ€ť actually works on surfaces too.
So in case you construct â€śsolid cuttersâ€ť instead of just a bunch of curves for splitting, there would be no need to remove/select anything because the other parts are already gone.
might come in handy in some situation.

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When using `Surface Split`, the output pieces arenâ€™t always organized in a nice way. This is meant to organize all the pieces by the V coordinate of their center point. Given the simple shape, this is enough here.
`Area` gives the centroid which is taken as a representative point for the global stripe position in space, it it then projected back on the surface to get its UV coordinates. Point is deconstructed into X Y Z but really here itâ€™s U V and W. Then sort all Vs in increasing order with `Sort list`, and sort the stripes simultaneously. It you plug a` List Item` after Values A youâ€™ll see the stripes are in order.

`Trim Tree` reduces the tree depth by 1. It is necessary to put back all groups of pieces in one list per base face (one branch) to be able to select only some elements of that list.
You cannot really see its effect here since you arenâ€™t using the Draw Fancy Wires mode which is highly unrecommended. Insert a Panel before and after this component and youâ€™ll see the tree changing structure.

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Dear magicteddy,
I am starting to understand what you said! Your help has been incredibly useful for learning Grasshopper. I apologize for any confusion, but I truly appreciate your assistance.
Best regards,
Keisuke

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