Is there a way to bend a triangle along the z axis in OpenSCAD?

Question

I have drawn a triangle in openSCAD using a function/module to give it rounded edges (Largely because I was being slightly lazy, but also because I didn't want to mess this up). I now want to bend the triangle from the top to the bottom.

        
fn=128;


    RoundedPolygon([[0,0],[120,260],[230,0]],25,fn);

module RoundedPolygon(P,r,fn)
{
    rotate(a=90, v=[0,0,1]){
    rotate([90,180,180]) scale([1,1,5]) 
        {
    v = rounded_polygon_v(P,r,fn);
    polygon(v);};};
    
}

function bezier_smooth(path_pts, round_d, t_step = 0.1, closed = false, angle_threshold = 0) =
    _bezier_smooth_impl(path_pts, round_d, t_step, closed, angle_threshold);

function rounded_polygon_v(P,r,fn) =
let
(
    step = 360 / fn,
    n = len(P),
    o_v = [ for(i=[0:n-1]) atan2(P[(i+1)%n][1] - P[i][1], P[(i+1)%n][0] - P[i][0]) + 90 + 360 ]
)
[ 
        for(i=[0:n-1])
            let 
            (
                n1 = i, 
                n2 = (i+1)%n,
                w1 = o_v[n1],
                w2 = (o_v[n2] < w1) ? o_v[n2] : o_v[n2] - 360
            )
            for (w=[w1:-step:w2]) 
                [ cos(w)*r+P[n2][0], sin(w)*r+P[n2][1] ] 
] ;

It works but no matter how I TRY to bend it (from bottom to top or top to bottom, along the z axis (I think that's how you'd describe it anyway).

Does anyone have any tricks or tips in openSCAD to do this?

Answer 1

r1=200;
r2=100;

for (deg=[0:1:180]){
    
    x1=cos(deg)*r1;
    z1=sin(deg)*r2;  
    x2=cos(deg+1)*r1;
    z2=sin(deg+1)*r2;
    
    hull(){
        translate([x1,0,z1])cube([1,deg,1],true);         
        translate([x2,0,z2])cube([1,deg,1],true);
    }
}

Answer 2

This module bend.scad bends any objects such as text and even svg flat graphics to cylinder surface. See examples in the end of file. https://github.com/Broshward/3D_models/blob/main/bend.scad