Reference Help

General discussion about Origami, Papers, Diagramming, ...

Re: Reference Help

Postby Baltorigamist » February 13th, 2019, 11:33 pm

It's possible one of us miscalculated. Regardless, I figured it out with the image you sent me.
ImageFor Tankoda (Take 2) by DirgeOfDreams, on Flickr
After the fall, we rise.

My Flickr
Baltorigamist
Moderator
 
Posts: 2157
Joined: December 25th, 2011, 7:15 pm
Location: Inside my twisted little mind....

Reference point location help

Postby Ori-JD » July 11th, 2019, 9:52 am

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

Image
Ori-JD
Newbie
 
Posts: 23
Joined: July 24th, 2009, 7:36 am

Re: Reference point location help

Postby Splunge » July 11th, 2019, 11:59 am

Hello,

my estimation in Oripa resulted in the following:
Image
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:
Image
splunge.de - Origami, Papercraft, Scale models, Photography
User avatar
Splunge
Newbie
 
Posts: 49
Joined: June 17th, 2016, 1:01 pm
Location: Germany

Re: Reference point location help

Postby Ori-JD » July 11th, 2019, 12:37 pm

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...
Ori-JD
Newbie
 
Posts: 23
Joined: July 24th, 2009, 7:36 am

Re: Reference point location help

Postby Baltorigamist » July 11th, 2019, 9:41 pm

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.
After the fall, we rise.

My Flickr
Baltorigamist
Moderator
 
Posts: 2157
Joined: December 25th, 2011, 7:15 pm
Location: Inside my twisted little mind....

Previous

Return to General Origami Talk

Who is online

Users browsing this forum: No registered users and 2 guests