Great Guenther

On Sun, 5 Nov, 2023, 5:40 pm Guenther Sohler via Discuss, <
discuss@lists.openscad.org> wrote:

Can something similar be done just with OpenSCAD, perhaps using a library?

On 11/5/2023 7:39 AM, Sanjeev Prabhakar via Discuss wrote:

Hi John,

I am confident that this is possible with OpenSCAD only. I would guess this
is included in BOSL2, maybe Inphase's closepoints
function can exactly do that as well.
The advantage here is that the functionality is exactly there, where you
expect it(at rotate_extrude).(And you additionally have the option to add
more sophisticated things like more formulas, calculations, or e.g. getting
data from a file)

The callback thing is not yet final, trying to get it more general(like
using same for linear_extrude and path_extrude) and/or get the most
important set of parameters to rotate_extrude
but the main idea is there already i would say

Guenther

On Sun, Nov 5, 2023 at 2:10 PM jon via Discuss discuss@lists.openscad.org
wrote:

Eh, sorta?  BOSL2 doesn't specifically have anything to generate this from a function, but I suspect it'd be trivial to generate a set of vertices to pass to vnf_vertex_array() in a few lines of code.  I'd have to know a few things first, though:

• Are the ang1 and ang2 arguments to profile() equivalent to theta and phi in cylindrical coordinates, relative to the origin?
• Is ang2 going from 0 to 180, or from -90 to 90, or is it a full 360 sweep?
• What does the offset argument to your rotate_extrude() do?

• Revar

Nevermind.  I figured it out.

include <BOSL2/std.scad>
liss_fn = function(ang1,ang2) (2+cos(3*ang2)+0.25*cos(3*ang2))*(1+sin(ang1)/2);
module rotate_sweep_by_func(fn,offset) {
    rows = [
        for (ang1=[0:5:360])
        let(
            profile = [
                for (ang2=[0:5:360])
                offset + polar_to_xy(liss_fn(ang1,ang2), ang2)
            ]
        )
        zrot(ang1, p=xrot(90, p=path3d(profile)))
    ];
    vnf = vnf_vertex_array(rows);
    vnf_polyhedron(vnf, convexity=10);
}
rotate_sweep_by_func(liss_fn, offset=[3,0]);



• Revar