I am trying to create seperate surfaces between each line from this geometry generated solely in Grasshopper. I have generated points at each intersection. The geometry is modelling a building facade and I have generated it parametrically so the size/number of divisions/position of divisions can be changed. The intended purpose is to use this geometry to model in ladybug and diva so the surfaces need to be divided properly among the divisions. I have tried most of the surface tools using lines and grids. I assume the âsurface from pointsâ tool isnât working because the points are in the wrong order in the list, but because I have accumulated the list from various sources I donât know if I could order it correctly. Any help would be greatly appreciated.

perhaps you can use those lines and split the face of that box.

Iâd also recommend grouping the splitting lines by horizontal and vertical, and split in two steps

Could you explain what youâve done?

Iâm trying this method. When doing the split in two steps, after the first step and then using the âbranchâ tool to isolate the split surfaces, when I try and input the list of split surfaces into the vertical line split its saying âdata conversion failed from text to surfaceâ

Iâll try:

- created points at intersections
- sorted them according to x,y,z
- removed duplicate points (by this time, points are a single, ordered list)
- for every point n, (apart from the top and the right ones), I created a surface with n+1, n+4 and n+5

This is useful for a old method I tried using points at corners which Iâve already generated, but the list was unordered and duplicated so it wouldnât work. Thanks.

Sounds like you are running data through a text panel? That wonât work. Bad practice because what comes out of a text panel is text, not the geometry that went in.

Uploading your own GH file is strongly recommended.

I could upload it once Iâve cleaned it up but at the moment itâs long and complicated and would be difficult to follow. Thanks for your help though that solved an issue. Now it is splitting through some lines but not all so I need to figure out why

Hi Im trying your method usng points as it has the advantage of sorting the points in x and y. With the part of your sheet leading into i for the list item component, what are you doing?

I think I got it. Did you set the input for the first item series component step size as 4 using the expression? I need to set my C values parametrically and using conditional statements then it should work (as I have changing geometry)

lets say there are x (columns) by y (rows) points,

I created a flat list where every yth point was left out.

e.g. if there were 4 rows the list produced is 1,2,3,5,6,7,9,10,11, ,âŚ and the las triad would also be left out.

that way, from the flat list of points we exclude the top-most and the right-most points.

then for an n point, I created a surface together with the points n+1, n+y, n+y+1

(the n+y and n+y+1 by definition will be the equivalent points for n and n+1 in the following column.)

thatâs why I had to leave out the outermost points so as not to have âwrapâ surfaces at the end.

hope that makes sense!

(itâs always more difficult to explain it than to think it!)

Thanks. What did you do for the step n in your first series?

oh man, youâr squeezing my brain

as I remember: (again for x rows, y columns)

first list: a series of y-1 numbers that are multiples of x

second list: for every number ânâ of the previous list, a list came out (n, n+1, n+2,âŚn+(x-2)

so as to get the pattern of indices:

**1**, 2,âŚ, x-2,-void-,

**x**, x+1,âŚ, x+(x-2), -void-,

**2*x**, 2*x+1,âŚ

(adjusted for counting from zero- I am not at a computer with rhino and Iâm doing it from memory now)

essential part is you want to create a âx*(y-1)â long list of indices were every (x*n)-1 value is missing

It has worked with 4 for now, essentially telling it that one step is one rectangular surface. However it broke once with this number but maybe that was a parameterisation error

The answer to your question is very clear from reading the code. The expression on the `Series` âNâ input is âx+1â. Can you see that? It has a âRowsâ slider plugged into it with the integer value of 3, so âx+1â = 4.

Here we have another solution using `Isotrim`with custom divisionâŚ

Custom_Div_Isotrim_re.gh (14.3 KB)

Thanks everyone. I have solved the problem now with your help. It was a matter of correct ordering.