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Last active Sep 16, 2020
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An extremely hacky bit of code to split an SVG of joined line paths into individual lines, and merge straight lines made of smaller lines into single lines
# An extremely hacky bit of code that takes SVG files output by Blender
# and splits all the multi-node line paths into single line paths to make
# editing easier. Example: A right-angle path is now two lines that meet.
# Blender has a habit of outputting really _weird_ paths that are annoying
# to edit on geometric shapes, and also outputs straight lines that are
# made up of many smaller straight line nodes. This code also merges those
# mini-line lines into single lines to stop you throwing your computer out
# of the window when you try and work with the SVG.
# The SVG parsing in this is hilarious and lazy because I only ever needed
# to use this once. It will likely not work with SVG output from any other
# program, or even different types of SVG from Blender - but just in case
# here's the code. I couldn't find anyone else doing this.
import sys
import re
import math
with open(sys.argv[1]) as f:
for line in f.readlines():
line = line.strip()
matches ='(\s*<path d=" M )([^"]+)( ".*)$', line)
if matches:
tail =
tail = tail.replace('stroke-width="3.0"', 'stroke-width="1.0"')
lines = []
# Split into individual lines
coords = re.findall('(\d+\.\d+, \d+.\d+)',
last_coord = coords.pop(0)
for coord in coords:
lines.append((last_coord, coord))
last_coord = coord
# Merge lines that are part of a contiguous line
merged_lines = []
last_line = lines.pop(0)
last_point = last_line[0]
for line in lines:
# Last segment
x1, y1 = last_line[0].split(", ")
x2, y2 = last_line[1].split(", ")
last_slope = math.atan2(float(x2) - float(x1), float(y2) - float(y1))
# This segment
x1, y1 = line[0].split(", ")
x2, y2 = line[1].split(", ")
this_slope = math.atan2(float(x2) - float(x1), float(y2) - float(y1))
if abs(last_slope - this_slope) > 0.01:
merged_lines.append((last_point, last_line[1]))
last_point = line[0]
last_line = line
merged_lines.append((last_point, last_line[1]))
for line in merged_lines:
print("%s%s %s%s" % (, line[0], line[1], tail))
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