## Reference Help

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### Re: Reference Help

It's possible one of us miscalculated. Regardless, I figured it out with the image you sent me.
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Baltorigamist
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### Reference point location help

Hello,

I am designing a model and this picture is the fundamental structure of the crease pattern. I would like some help to locate reference points to be able to fold this pattern from a square of any given size. And if it's not too much, I'd also like a mathematical explanation as to how to do this for my own future benefit. Thanks

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### Re: Reference point location help

Hello,

my estimation in Oripa resulted in the following:

So it's based on a 30x30 grid

However, it doesn't exactly match your drawing, so I don't know if it's of any help for you:
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### Re: Reference point location help

I drew the CP in Adobe illustrator and tried determining what grid system it's using - but with no success. If I make the whole square 100 x 100mm, those three smaller squares are approximately 16.866 mm wide, while the slightly larger one is 19.76 mm wide.

I originally built the CP on a 10 x 10 grid, but made necessary structural changes. If you stack 10 squares from the bottom of the CP (aligning them perfectly with the existing edge creases), then you are left with 1.191 mm of space at the top...
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### Re: Reference point location help

Splunge, your estimation is off because it’s not based on a grid. It’s a complex irrational proportion that happens to almost lie on a grid.

Let me get back to you on this one. It will take some time to work out. In the meantime, draw lines from the corners through important points. They might hit the edges at easy-to-find points.
Also, I merged your topic with an existing one that covers reference points.

EDIT: as a starting point, each of the diagonals at the bottom left has length 2 (meaning the squares they form have side length 2sqrt2). Following that proportion, the squares stacked up to the top edge have side length 1+sqrt2. So the larger and smaller squares meet at 3+(3sqrt2) : 5sqrt2. (This is the top : bottom ratio.) As to why Splunge thought it was based on a grid, that line is 49.4% down from the top edge of the square.
I’ll try to work out a way to find that proportion tonight.
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### Re: Reference Help

Forgive the double post, but I just decided to revisit this in case you’re still wondering how to find it. The ratio I came up with this time (top : bottom) is (9+(6sqrt2)) : (10+(5sqrt2)). I’ll have to crunch the numbers a little more to find the exact ratio, but as of now I don’t think it simplifies down.
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