blender (sverchok) nodetree to svg

beginnings_of_simple_svg.py

import os
import re

import bpy
import sverchok

from dataclasses import dataclass
from xml.etree import ElementTree as et

@dataclass
class NodeProxy():
    name: str
    label: str
    abs_location: tuple
    width: float
    num_linked_inputs: dict
    num_linked_outputs: dict


nt = bpy.data.node_groups['NodeTree']
nt_dict = {}
for n in nt.nodes:
    inputs = {s.name: (s.index, s.is_linked) for s in n.inputs}
    outputs = {s.name: (s.index, s.is_linked) for s in n.outputs}
    nt_dict[n.name] = NodeProxy(n.name, n.label, tuple(int(i) for i in n.absolute_location), n.width, inputs, outputs)

doc = et.Element('svg', width='1480', height='960', version='1.1', xmlns='http://www.w3.org/2000/svg')
gdoc = et.SubElement(doc, "g", transform=f"translate({430}, {330})")
ldoc = et.SubElement(doc, "g", transform=f"translate({430}, {330})")

for k, v in nt_dict.items():
    g = et.SubElement(gdoc, "g", transform=f"translate{v.abs_location}")
    m = et.SubElement(g, "rect", width=str(v.width), height=str(40), fill='rgb(74, 177, 231)')
    t = et.SubElement(g, "text", fill="#333", y="-2", x="3")
    t.text = v.name

#       style="fill-opacity: .25;")
# https://github.com/nortikin/sverchok/issues/2360
for link in nt.links:
    n1, s1, n2, s2 = link.from_node, link.from_socket, link.to_node, link.to_socket
    (x1, y1), (x2, y2) = n1.absolute_location, n2.absolute_location
    ctrl_1 = int(x1) + n1.width + 180, int(y1)
    knot_1 = int(x1) + n1.width + 20,  int(y1)
    knot_2 = int(x2) - 20,             int(y2)
    ctrl_2 = int(x2) - 180,            int(y2)
    dpath = f"M{knot_1} C{ctrl_1} {ctrl_2} {knot_2}"
    dpath = re.sub("\(|\)", "", dpath)
    path = et.SubElement(ldoc, "path", d=dpath, stroke_width="3.0", stroke="#333", fill="transparent") 


svg_filename = "wooooop"
svg_path = os.path.join(bpy.path.abspath('//'), svg_filename + '.svg')
with open(svg_path, 'w') as f:
    f.write('\n\n')
    f.write(et.tostring(doc).decode())

this shows how to

• add a group,
• transform the group,
• add svg elements to a group.
• add text to text element
• add fill
• how to write to disk