<![CDATA[function to create regular polygon]]>Hello, I'm making a design made from a polyhedron and am needing to make regular polygons having same side length. I have a V1 script to do that and before to port it to V2, I was wondering whether it could be done straightly using
a function to compute the radius depending on the side length and the number of segments.
Do you thing such function is possible ?

function RegularPolygon(sideLength, sidesCount){
  let R = ...
return circle ({radius: R, segments: sidesCount})
}

But on the other side, maybe is it better to stop using the segment trick, and by the way, I remember that there is star(), but isn't there it's counterpart that would create regular polygon ?

]]>https://openjscad.nodebb.com/topic/322/function-to-create-regular-polygonRSS for NodeSun, 15 Mar 2026 05:30:52 GMTWed, 01 Dec 2021 09:32:54 GMT60<![CDATA[Reply to function to create regular polygon on Wed, 01 Dec 2021 10:25:14 GMT]]>@hrgdavor Thanks a lot that's exactly what I needed,
Capture d’écran de 2021-12-01 11-24-28.png

]]>https://openjscad.nodebb.com/post/1026https://openjscad.nodebb.com/post/1026Wed, 01 Dec 2021 10:25:14 GMT<![CDATA[Reply to function to create regular polygon on Wed, 01 Dec 2021 10:07:49 GMT]]>@gilboonet not sure if this is what u need
7094d8db-ba0c-4bb1-8b49-8401b616acee-image.png

α angle of the triangle is Math.PI/sidesCount in radians or 360/sidesCount/2 in degrees
red line is A = Math.sin(α)
blue line is A=Math.cos(α)
the radius you are looking for the circle isR=1 in this drawing

R=sideLength/2/Math.sin(α)
or
sideLength=(R*Math.sin(α)) * 2


const jscad = require('@jscad/modeling')
// https://openjscad.xyz/docs/module-modeling_primitives.html
const { circle } = jscad.primitives

function main({// @jscad-params
	sideLength = 15,
	sidesCount = 6,
}){
	let alpha = Math.PI / sidesCount
	let R = sideLength/2/Math.sin(alpha)
	// R === sideLength in case of sideCount=6 (hexagon)
	console.log('R',R)
	return circle({radius:R, segments: sidesCount})
}

module.exports = {main}
]]>https://openjscad.nodebb.com/post/1025https://openjscad.nodebb.com/post/1025Wed, 01 Dec 2021 10:07:49 GMT