Based on my very simple editor from
Construction of frames with contour/profile,
and the triangulation
Addon for triangulation of implicit surfaces/ forms with holes
and
Triangulation cylinder with holes
I have created a web editor for single-branched geometries.
It is published on GitHub under a license that permits private use and use for educational purposes,
but not commercial use. ==>> See GitHub for details.
A simple example
Several values and options can be set in the modal start dialog. You can start a new design or import a saved design.
The manual/help is available as a pdf file in English
and German
Below are links on the graphic of Etterstudio
https://etterstudio.com/
and on my avatar hofk (Klaus Hoffmeister) · GitHub , which was created with this software.
The generated geometries can be saved as a three.js geometry definition or as a mesh in GLTF format.
On the page Showcase: SingleBranchedGeometryEditor
you can find some pictures. These geometries can be created quite quickly with the editor.
Some operating steps can be seen in videos. Showcase: SingleBranchedGeometryEditor
Please note the keys to be pressed when moving the mouse.
use and educational purposes 
, but not for commercial 
use.