Using GDL to write parameterized iron chains

[yongler]

In some scenic spots in Hangzhou, China, chains are used as railings, and the top of pagodas is fixed with iron chains. Like the picture. This kind of iron chain is written in GDL language. The hot spot at one end can be dragged, and the sag arc in the middle can also be controlled. Another key parameter is that each iron ring rotates by 90 °

 

 

[Laszlo Nagy]

Yeah, ChatGPT is a GDL Noob. 🙂

[yongler]

GDL is not popular, so developers of chatGPT have not input GDL information?

GDL may be the  forever blind zone of chatGPT ? 😎

[Hmooslechner]

Maybe a rope instead?

Make Your own... with the profilemaker and my GDL - a few changes in 3D-script:

[yongler]

 

[julienK]

I managed to achieve this with a proper catenary curve. 

As Hmooslechner mentioned the hard part was to get equidistant points along the curve to generate the chain links.  I used an approximation method that works just fine.

I converted this method found on YouTube  https://www.youtube.com/watch?v=gkdnS6rISV0 to work in GDL, but this method generates points at fix intervals along the X axis so the greater the slope the greater the distance between points along the curve.

To fix this I calculate the tangent angle at  point n on the curve then  generate the point n+1 at cos(tangent angle) along the x axis. This generates equidistant points along then curve.

Both anchors can be moved around

 

The length of the chain can be adjusted without moving the anchors.

The links of the chain are fully customizable.

    And it can be displayed as a cable

 

[Hmooslechner]

That was much too much maths for me!  😂 - Where and when and how will we (the cummunity) get this? 😇

[julienK]

I'll make a commercial version available for purchase on monday. PM me if interested.

[jl_lt · Accepted solution]

For those of us who ever toyed with the idea of trying to learn gdl, this has been beautiful to read and terrifying at the same time.  I congratulate you all guys

Cheers!

[Hmooslechner]

In my mind, some solutions for that without the intensive amounts of maths are rumbling in the cellars of my mind, but i can wait to realize them until You have made Your money.. How long do you think I should wait until your expenses are financially recouped?   😇