Fix for Freestyle SVG Export

I am not a developer, but I use blender 2.8 and noticed the Freestyle SVG Export addon is broken. It was simply referencing bpy.context.scene.render.layers.active.freestyle_settings rather than the updated bpy.context.window.view_layer.freestyle_settings . (These were at line 192 and 268 if it matters)
I know a little python so it was easy to fix, but I don’t know anything about git commits or blender development, so I figured I could maybe put the fixed code here and let somebody else put it into the blender codebase.
Hopefully I’m not being annoying; here ya go.

# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####

# <pep8 compliant>

bl_info = {
    "name": "Freestyle SVG Export",
    "author": "Folkert de Vries",
    "version": (1, 0),
    "blender": (2, 80, 0),
    "location": "Properties > Render > mosesfreestyle",
    "description": "Exports Freestyle's stylized edges in SVG format",
    "warning": "",
    "wiki_url": "",
    "category": "Render",
    }

import bpy
import parameter_editor
import itertools
import os

import xml.etree.cElementTree as et

from bpy.app.handlers import persistent
from collections import OrderedDict
from functools import partial
from mathutils import Vector

from freestyle.types import (
        StrokeShader,
        Interface0DIterator,
        Operators,
        Nature,
        StrokeVertex,
        )
from freestyle.utils import (
    getCurrentScene,
    BoundingBox,
    is_poly_clockwise,
    StrokeCollector,
    material_from_fedge,
    get_object_name,
    )
from freestyle.functions import (
    GetShapeF1D,
    CurveMaterialF0D,
    )
from freestyle.predicates import (
        AndBP1D,
        AndUP1D,
        ContourUP1D,
        ExternalContourUP1D,
        MaterialBP1D,
        NotBP1D,
        NotUP1D,
        OrBP1D,
        OrUP1D,
        pyNatureUP1D,
        pyZBP1D,
        pyZDiscontinuityBP1D,
        QuantitativeInvisibilityUP1D,
        SameShapeIdBP1D,
        TrueBP1D,
        TrueUP1D,
        )
from freestyle.chainingiterators import ChainPredicateIterator
from parameter_editor import get_dashed_pattern

from bpy.props import (
        BoolProperty,
        EnumProperty,
        PointerProperty,
        )


# use utf-8 here to keep ElementTree happy, end result is utf-16
svg_primitive = """<?xml version="1.0" encoding="ascii" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="{:d}" height="{:d}">
</svg>"""


# xml namespaces
namespaces = {
    "inkscape": "http://www.inkscape.org/namespaces/inkscape",
    "svg": "http://www.w3.org/2000/svg",
    "sodipodi": "http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd",
    "": "http://www.w3.org/2000/svg",
    }


# wrap XMLElem.find, so the namespaces don't need to be given as an argument
def find_xml_elem(obj, search, namespaces, *, all=False):
    if all:
        return obj.findall(search, namespaces=namespaces)
    return obj.find(search, namespaces=namespaces)

find_svg_elem = partial(find_xml_elem, namespaces=namespaces)


def render_height(scene):
    return int(scene.render.resolution_y * scene.render.resolution_percentage / 100)


def render_width(scene):
    return int(scene.render.resolution_x * scene.render.resolution_percentage / 100)


def format_rgb(color):
    return 'rgb({}, {}, {})'.format(*(int(v * 255) for v in color))


# stores the state of the render, used to differ between animation and single frame renders.
class RenderState:

    # Note that this flag is set to False only after the first frame
    # has been written to file.
    is_preview = True


@persistent
def render_init(scene):
    RenderState.is_preview = True


@persistent
def render_write(scene):
    RenderState.is_preview = False


def is_preview_render(scene):
    return RenderState.is_preview or scene.svg_export.mode == 'FRAME'


def create_path(scene):
    """Creates the output path for the svg file"""
    path = os.path.dirname(scene.render.frame_path())
    file_dir_path = os.path.dirname(bpy.data.filepath)

    # try to use the given path if it is absolute
    if os.path.isabs(path):
        dirname = path

    # otherwise, use current file's location as a start for the relative path
    elif bpy.data.is_saved and file_dir_path:
        dirname = os.path.normpath(os.path.join(file_dir_path, path))

    # otherwise, use the folder from which blender was called as the start
    else:
        dirname = os.path.abspath(bpy.path.abspath(path))


    basename = bpy.path.basename(scene.render.filepath)
    if scene.svg_export.mode == 'FRAME':
        frame = "{:04d}".format(scene.frame_current)
    else:
        frame = "{:04d}-{:04d}".format(scene.frame_start, scene.frame_end)

    return os.path.join(dirname, basename + frame + ".svg")


class SVGExporterLinesetPanel(bpy.types.Panel):
    """Creates a Panel in the Render Layers context of the properties editor"""
    bl_idname = "RENDER_PT_SVGExporterLinesetPanel"
    bl_space_type = 'PROPERTIES'
    bl_label = "Freestyle Line Style SVG Export"
    bl_region_type = 'WINDOW'
    bl_context = "render_layer"

    def draw(self, context):
        layout = self.layout

        scene = context.scene
        svg = scene.svg_export
        freestyle = window.view_layer.freestyle_settings

        try:
            linestyle = freestyle.linesets.active.linestyle

        except AttributeError:
            # Linestyles can be removed, so 0 linestyles is possible.
            # there is nothing to draw in those cases.
            # see https://developer.blender.org/T49855
            return

        else:
            layout.active = (svg.use_svg_export and freestyle.mode != 'SCRIPT')
            row = layout.row()
            column = row.column()
            column.prop(linestyle, 'use_export_strokes')

            column = row.column()
            column.active = svg.object_fill
            column.prop(linestyle, 'use_export_fills')

            row = layout.row()
            row.prop(linestyle, "stroke_color_mode", expand=True)


class SVGExport(bpy.types.PropertyGroup):
    """Implements the properties for the SVG exporter"""
    bl_idname = "RENDER_PT_svg_export"

    use_svg_export: BoolProperty(
            name="SVG Export",
            description="Export Freestyle edges to an .svg format",
            )
    split_at_invisible: BoolProperty(
            name="Split at Invisible",
            description="Split the stroke at an invisible vertex",
            )
    object_fill: BoolProperty(
            name="Fill Contours",
            description="Fill the contour with the object's material color",
            )
    mode: EnumProperty(
            name="Mode",
            items=(
                ('FRAME', "Frame", "Export a single frame", 0),
                ('ANIMATION', "Animation", "Export an animation", 1),
                ),
            default='FRAME',
            )
    line_join_type: EnumProperty(
            name="Linejoin",
            items=(
                ('MITER', "Miter", "Corners are sharp", 0),
                ('ROUND', "Round", "Corners are smoothed", 1),
                ('BEVEL', "Bevel", "Corners are bevelled", 2),
                ),
            default='ROUND',
            )


class SVGExporterPanel(bpy.types.Panel):
    """Creates a Panel in the render context of the properties editor"""
    bl_idname = "RENDER_PT_SVGExporterPanel"
    bl_space_type = 'PROPERTIES'
    bl_label = "Freestyle SVG Export"
    bl_region_type = 'WINDOW'
    bl_context = "render"

    def draw_header(self, context):
        self.layout.prop(context.scene.svg_export, "use_svg_export", text="")

    def draw(self, context):
        layout = self.layout

        scene = context.scene
        svg = scene.svg_export
        freestyle = context.window.view_layer.freestyle_settings

        layout.active = (svg.use_svg_export and freestyle.mode != 'SCRIPT')

        row = layout.row()
        row.prop(svg, "mode", expand=True)

        row = layout.row()
        row.prop(svg, "split_at_invisible")
        row.prop(svg, "object_fill")

        row = layout.row()
        row.prop(svg, "line_join_type", expand=True)


@persistent
def svg_export_header(scene):
    if not (scene.render.use_freestyle and scene.svg_export.use_svg_export):
        return

    # write the header only for the first frame when animation is being rendered
    if not is_preview_render(scene) and scene.frame_current != scene.frame_start:
        return

    # this may fail still. The error is printed to the console.
    with open(create_path(scene), "w") as f:
        f.write(svg_primitive.format(render_width(scene), render_height(scene)))


@persistent
def svg_export_animation(scene):
    """makes an animation of the exported SVG file """
    render = scene.render
    svg = scene.svg_export

    if render.use_freestyle and svg.use_svg_export and not is_preview_render(scene):
        write_animation(create_path(scene), scene.frame_start, render.fps)


def write_animation(filepath, frame_begin, fps):
    """Adds animate tags to the specified file."""
    tree = et.parse(filepath)
    root = tree.getroot()

    linesets = find_svg_elem(tree, ".//svg:g[@inkscape:groupmode='lineset']", all=True)
    for i, lineset in enumerate(linesets):
        name = lineset.get('id')
        frames = find_svg_elem(lineset, ".//svg:g[@inkscape:groupmode='frame']", all=True)
        n_of_frames = len(frames)
        keyTimes = ";".join(str(round(x / n_of_frames, 3)) for x in range(n_of_frames)) + ";1"

        style = {
            'attributeName': 'display',
            'values': "none;" * (n_of_frames - 1) + "inline;none",
            'repeatCount': 'indefinite',
            'keyTimes': keyTimes,
            'dur': "{:.3f}s".format(n_of_frames / fps),
            }

        for j, frame in enumerate(frames):
            id = 'anim_{}_{:06n}'.format(name, j + frame_begin)
            # create animate tag
            frame_anim = et.XML('<animate id="{}" begin="{:.3f}s" />'.format(id, (j - n_of_frames) / fps))
            # add per-lineset style attributes
            frame_anim.attrib.update(style)
            # add to the current frame
            frame.append(frame_anim)

    # write SVG to file
    indent_xml(root)
    tree.write(filepath, encoding='ascii', xml_declaration=True)


# - StrokeShaders - #
class SVGPathShader(StrokeShader):
    """Stroke Shader for writing stroke data to a .svg file."""
    def __init__(self, name, style, filepath, res_y, split_at_invisible, stroke_color_mode, frame_current):
        StrokeShader.__init__(self)
        # attribute 'name' of 'StrokeShader' objects is not writable, so _name is used
        self._name = name
        self.filepath = filepath
        self.h = res_y
        self.frame_current = frame_current
        self.elements = []
        self.split_at_invisible = split_at_invisible
        self.stroke_color_mode = stroke_color_mode # BASE | FIRST | LAST
        self.style = style


    @classmethod
    def from_lineset(cls, lineset, filepath, res_y, split_at_invisible, use_stroke_color, frame_current, *, name=""):
        """Builds a SVGPathShader using data from the given lineset"""
        name = name or lineset.name
        linestyle = lineset.linestyle
        # extract style attributes from the linestyle and scene
        svg = getCurrentScene().svg_export
        style = {
            'fill': 'none',
            'stroke-width': linestyle.thickness,
            'stroke-linecap': linestyle.caps.lower(),
            'stroke-opacity': linestyle.alpha,
            'stroke': format_rgb(linestyle.color),
            'stroke-linejoin': svg.line_join_type.lower(),
            }
        # get dashed line pattern (if specified)
        if linestyle.use_dashed_line:
            style['stroke-dasharray'] = ",".join(str(elem) for elem in get_dashed_pattern(linestyle))
        # return instance
        return cls(name, style, filepath, res_y, split_at_invisible, use_stroke_color, frame_current)


    @staticmethod
    def pathgen(stroke, style, height, split_at_invisible, stroke_color_mode, f=lambda v: not v.attribute.visible):
        """Generator that creates SVG paths (as strings) from the current stroke """
        if len(stroke) <= 1:
            return ""

        if stroke_color_mode != 'BASE':
            # try to use the color of the first or last vertex
            try:
                index = 0 if stroke_color_mode == 'FIRST' else -1
                color = format_rgb(stroke[index].attribute.color)
                style["stroke"] = color
            except (ValueError, IndexError):
                # default is linestyle base color
                pass

        # put style attributes into a single svg path definition
        path = '\n<path ' + "".join('{}="{}" '.format(k, v) for k, v in style.items()) + 'd=" M '

        it = iter(stroke)
        # start first path
        yield path
        for v in it:
            x, y = v.point
            yield '{:.3f}, {:.3f} '.format(x, height - y)
            if split_at_invisible and v.attribute.visible is False:
                # end current and start new path;
                yield '" />' + path
                # fast-forward till the next visible vertex
                it = itertools.dropwhile(f, it)
                # yield next visible vertex
                svert = next(it, None)
                if svert is None:
                    break
                x, y = svert.point
                yield '{:.3f}, {:.3f} '.format(x, height - y)
        # close current path
        yield '" />'

    def shade(self, stroke):
        stroke_to_paths = "".join(self.pathgen(stroke, self.style, self.h, self.split_at_invisible, self.stroke_color_mode)).split("\n")
        # convert to actual XML. Empty strokes are empty strings; they are ignored.
        self.elements.extend(et.XML(elem) for elem in stroke_to_paths if elem) # if len(elem.strip()) > len(self.path))

    def write(self):
        """Write SVG data tree to file """
        tree = et.parse(self.filepath)
        root = tree.getroot()
        name = self._name
        scene = bpy.context.scene

        # create <g> for lineset as a whole (don't overwrite)
        # when rendering an animation, frames will be nested in here, otherwise a group of strokes and optionally fills.
        lineset_group = find_svg_elem(tree, ".//svg:g[@id='{}']".format(name))
        if lineset_group is None:
            lineset_group = et.XML('<g/>')
            lineset_group.attrib = {
                'id': name,
                'xmlns:inkscape': namespaces["inkscape"],
                'inkscape:groupmode': 'lineset',
                'inkscape:label': name,
                }
            root.append(lineset_group)

        # create <g> for the current frame
        id = "frame_{:04n}".format(self.frame_current)

        stroke_group = et.XML("<g/>")
        stroke_group.attrib = {
            'xmlns:inkscape': namespaces["inkscape"],
            'inkscape:groupmode': 'layer',
            'id': 'strokes',
            'inkscape:label': 'strokes'
            }
        # nest the structure
        stroke_group.extend(self.elements)
        if scene.svg_export.mode == 'ANIMATION':
            frame_group = et.XML("<g/>")
            frame_group.attrib = {'id': id, 'inkscape:groupmode': 'frame', 'inkscape:label': id}
            frame_group.append(stroke_group)
            lineset_group.append(frame_group)
        else:
            lineset_group.append(stroke_group)

        # write SVG to file
        print("SVG Export: writing to", self.filepath)
        indent_xml(root)
        tree.write(self.filepath, encoding='ascii', xml_declaration=True)


class SVGFillBuilder:
    def __init__(self, filepath, height, name):
        self.filepath = filepath
        self._name = name
        self.stroke_to_fill = partial(self.stroke_to_svg, height=height)

    @staticmethod
    def pathgen(vertices, path, height):
        yield path
        for point in vertices:
            x, y = point
            yield '{:.3f}, {:.3f} '.format(x, height - y)
        yield ' z" />'  # closes the path; connects the current to the first point


    @staticmethod
    def get_merged_strokes(strokes):
        def extend_stroke(stroke, vertices):
            for vert in map(StrokeVertex, vertices):
                stroke.insert_vertex(vert, stroke.stroke_vertices_end())
            return stroke

        base_strokes = tuple(stroke for stroke in strokes if not is_poly_clockwise(stroke))
        merged_strokes = OrderedDict((s, list()) for s in base_strokes)

        for stroke in filter(is_poly_clockwise, strokes):
            for base in base_strokes:
                # don't merge when diffuse colors don't match
                if diffuse_from_stroke(stroke) != diffuse_from_stroke(stroke):
                    continue
                # only merge when the 'hole' is inside the base
                elif stroke_inside_stroke(stroke, base):
                    merged_strokes[base].append(stroke)
                    break
                # if it isn't a hole, it is likely that there are two strokes belonging
                # to the same object separated by another object. let's try to join them
                elif (get_object_name(base) == get_object_name(stroke) and
                      diffuse_from_stroke(stroke) == diffuse_from_stroke(stroke)):
                    base = extend_stroke(base, (sv for sv in stroke))
                    break
            else:
                # if all else fails, treat this stroke as a base stroke
                merged_strokes.update({stroke:  []})
        return merged_strokes


    def stroke_to_svg(self, stroke, height, parameters=None):
        if parameters is None:
            *color, alpha = diffuse_from_stroke(stroke)
            color = tuple(int(255 * c) for c in color)
            parameters = {
                'fill_rule': 'evenodd',
                'stroke': 'none',
                'fill-opacity': alpha,
                'fill': 'rgb' + repr(color),
            }
        param_str = " ".join('{}="{}"'.format(k, v) for k, v in parameters.items())
        path = '<path {} d=" M '.format(param_str)
        vertices = (svert.point for svert in stroke)
        s = "".join(self.pathgen(vertices, path, height))
        result = et.XML(s)
        return result

    def create_fill_elements(self, strokes):
        """Creates ElementTree objects by merging stroke objects together and turning them into SVG paths."""
        merged_strokes = self.get_merged_strokes(strokes)
        for k, v in merged_strokes.items():
            base = self.stroke_to_fill(k)
            fills = (self.stroke_to_fill(stroke).get("d") for stroke in v)
            merged_points = " ".join(fills)
            base.attrib['d'] += merged_points
            yield base

    def write(self, strokes):
        """Write SVG data tree to file """

        tree = et.parse(self.filepath)
        root = tree.getroot()
        scene = bpy.context.scene
        name = self._name

        lineset_group = find_svg_elem(tree, ".//svg:g[@id='{}']".format(self._name))
        if lineset_group is None:
            lineset_group = et.XML('<g/>')
            lineset_group.attrib = {
                'id': name,
                'xmlns:inkscape': namespaces["inkscape"],
                'inkscape:groupmode': 'lineset',
                'inkscape:label': name,
                }
            root.append(lineset_group)
            print('added new lineset group ', name)


        # <g> for the fills of the current frame
        fill_group = et.XML('<g/>')
        fill_group.attrib = {
            'xmlns:inkscape': namespaces["inkscape"],
            'inkscape:groupmode': 'layer',
            'inkscape:label': 'fills',
            'id': 'fills'
           }

        fill_elements = self.create_fill_elements(strokes)
        fill_group.extend(reversed(tuple(fill_elements)))
        if scene.svg_export.mode == 'ANIMATION':
            # add the fills to the <g> of the current frame
            frame_group = find_svg_elem(lineset_group, ".//svg:g[@id='frame_{:04n}']".format(scene.frame_current))
            frame_group.insert(0, fill_group)
        else:
            lineset_group.insert(0, fill_group)

        # write SVG to file
        indent_xml(root)
        tree.write(self.filepath, encoding='ascii', xml_declaration=True)


def stroke_inside_stroke(a, b):
    box_a = BoundingBox.from_sequence(svert.point for svert in a)
    box_b = BoundingBox.from_sequence(svert.point for svert in b)
    return box_a.inside(box_b)


def diffuse_from_stroke(stroke, curvemat=CurveMaterialF0D()):
    material = curvemat(Interface0DIterator(stroke))
    return material.diffuse

# - Callbacks - #
class ParameterEditorCallback(object):
    """Object to store callbacks for the Parameter Editor in"""
    def lineset_pre(self, scene, layer, lineset):
        raise NotImplementedError()

    def modifier_post(self, scene, layer, lineset):
        raise NotImplementedError()

    def lineset_post(self, scene, layer, lineset):
        raise NotImplementedError()



class SVGPathShaderCallback(ParameterEditorCallback):
    @classmethod
    def poll(cls, scene, linestyle):
        return scene.render.use_freestyle and scene.svg_export.use_svg_export and linestyle.use_export_strokes

    @classmethod
    def modifier_post(cls, scene, layer, lineset):
        if not cls.poll(scene, lineset.linestyle):
            return []

        split = scene.svg_export.split_at_invisible
        stroke_color_mode = lineset.linestyle.stroke_color_mode
        cls.shader = SVGPathShader.from_lineset(
                lineset, create_path(scene),
                render_height(scene), split, stroke_color_mode, scene.frame_current, name=layer.name + '_' + lineset.name)
        return [cls.shader]

    @classmethod
    def lineset_post(cls, scene, layer, lineset):
        if not cls.poll(scene, lineset.linestyle):
            return []
        cls.shader.write()


class SVGFillShaderCallback(ParameterEditorCallback):
    @classmethod
    def poll(cls, scene, linestyle):
        return scene.render.use_freestyle and scene.svg_export.use_svg_export and scene.svg_export.object_fill and linestyle.use_export_fills

    @classmethod
    def lineset_post(cls, scene, layer, lineset):
        if not cls.poll(scene, lineset.linestyle):
            return

        # reset the stroke selection (but don't delete the already generated strokes)
        Operators.reset(delete_strokes=False)
        # Unary Predicates: visible and correct edge nature
        upred = AndUP1D(
            QuantitativeInvisibilityUP1D(0),
            OrUP1D(ExternalContourUP1D(),
                   pyNatureUP1D(Nature.BORDER)),
            )
        # select the new edges
        Operators.select(upred)
        # Binary Predicates
        bpred = AndBP1D(
            MaterialBP1D(),
            NotBP1D(pyZDiscontinuityBP1D()),
            )
        bpred = OrBP1D(bpred, AndBP1D(NotBP1D(bpred), AndBP1D(SameShapeIdBP1D(), MaterialBP1D())))
        # chain the edges
        Operators.bidirectional_chain(ChainPredicateIterator(upred, bpred))
        # export SVG
        collector = StrokeCollector()
        Operators.create(TrueUP1D(), [collector])

        builder = SVGFillBuilder(create_path(scene), render_height(scene), layer.name + '_' + lineset.name)
        builder.write(collector.strokes)
        # make strokes used for filling invisible
        for stroke in collector.strokes:
            for svert in stroke:
                svert.attribute.visible = False



def indent_xml(elem, level=0, indentsize=4):
    """Prettifies XML code (used in SVG exporter) """
    i = "\n" + level * " " * indentsize
    if len(elem):
        if not elem.text or not elem.text.strip():
            elem.text = i + " " * indentsize
        if not elem.tail or not elem.tail.strip():
            elem.tail = i
        for elem in elem:
            indent_xml(elem, level + 1)
        if not elem.tail or not elem.tail.strip():
            elem.tail = i
    elif level and (not elem.tail or not elem.tail.strip()):
        elem.tail = i


def register_namespaces(namespaces=namespaces):
    for name, url in namespaces.items():
        if name != 'svg': # creates invalid xml
            et.register_namespace(name, url)

@persistent
def handle_versions(self):
    # We don't modify startup file because it assumes to
    # have all the default values only.
    if not bpy.data.is_saved:
        return

    # Revision https://developer.blender.org/rBA861519e44adc5674545fa18202dc43c4c20f2d1d
    # changed the default for fills.
    # fix by Sergey https://developer.blender.org/T46150
    if bpy.data.version <= (2, 76, 0):
        for linestyle in bpy.data.linestyles:
            linestyle.use_export_fills = True



classes = (
    SVGExporterPanel,
    SVGExporterLinesetPanel,
    SVGExport,
    )


def register():
    linestyle = bpy.types.FreestyleLineStyle
    linestyle.use_export_strokes = BoolProperty(
            name="Export Strokes",
            description="Export strokes for this Line Style",
            default=True,
            )
    linestyle.stroke_color_mode = EnumProperty(
            name="Stroke Color Mode",
            items=(
                ('BASE', "Base Color", "Use the linestyle's base color", 0),
                ('FIRST', "First Vertex", "Use the color of a stroke's first vertex", 1),
                ('FINAL', "Final Vertex", "Use the color of a stroke's final vertex", 2),
                ),
            default='BASE',
            )
    linestyle.use_export_fills = BoolProperty(
            name="Export Fills",
            description="Export fills for this Line Style",
            default=False,
            )

    for cls in classes:
        bpy.utils.register_class(cls)
    bpy.types.Scene.svg_export = PointerProperty(type=SVGExport)


    # add callbacks
    bpy.app.handlers.render_init.append(render_init)
    bpy.app.handlers.render_write.append(render_write)
    bpy.app.handlers.render_pre.append(svg_export_header)
    bpy.app.handlers.render_complete.append(svg_export_animation)

    # manipulate shaders list
    parameter_editor.callbacks_modifiers_post.append(SVGPathShaderCallback.modifier_post)
    parameter_editor.callbacks_lineset_post.append(SVGPathShaderCallback.lineset_post)
    parameter_editor.callbacks_lineset_post.append(SVGFillShaderCallback.lineset_post)

    # register namespaces
    register_namespaces()

    # handle regressions
    bpy.app.handlers.version_update.append(handle_versions)


def unregister():

    for cls in classes:
        bpy.utils.unregister_class(cls)
    del bpy.types.Scene.svg_export
    linestyle = bpy.types.FreestyleLineStyle
    del linestyle.use_export_strokes
    del linestyle.use_export_fills

    # remove callbacks
    bpy.app.handlers.render_init.remove(render_init)
    bpy.app.handlers.render_write.remove(render_write)
    bpy.app.handlers.render_pre.remove(svg_export_header)
    bpy.app.handlers.render_complete.remove(svg_export_animation)

    # manipulate shaders list
    parameter_editor.callbacks_modifiers_post.remove(SVGPathShaderCallback.modifier_post)
    parameter_editor.callbacks_lineset_post.remove(SVGPathShaderCallback.lineset_post)
    parameter_editor.callbacks_lineset_post.remove(SVGFillShaderCallback.lineset_post)

    bpy.app.handlers.version_update.remove(handle_versions)


if __name__ == "__main__":
    register()
3 Likes

I will add it tomorrow.

Glad to see that this contribution of an astounding two lines of code could make it into Blender. :slight_smile: Thanks dude!

What wasn’t working without the changes in lines 192 and 268?

The addon accessed some freestyle render settings through the active render layer. with the way blender data access (collections, etc.) changed, the api call to access the active renderlayer changed. When I enabled the addon, it raised an error when the code used the old api call. I had to change bpy.context.scene.render.layers.active.freestyle_settings to bpy.context.window.view_layer.freestyle_settings on those lines to get it to work.

here’s the error message the broken code would produce.
image

(I’m honestly a python beginner; I’m only good at fiddling with the python console and reading api references, so excuse my bad explanation. I have used this addon since I fixed it so I’m pretty confident it works now.)