svg2stl

This repository provides a script which takes as input an SVG such as this one:

It outputs an STL file like this:

You can also see an interactive version here.

The resulting solid is a cuboid with holes in it. It essentially adds a third dimension to the SVG file. The purpose of the output STL is to be fed into a 3D printer. The end goal is to make a physical stencil for artistic purposes.

Installation

git clone https://github.com/MaxHalford/svg2stl
cd svg2stl
pip install -r requirements.txt

Usage

You can generate an STL with the same name as the input file like this:

python svg2stl.py example.svg --thickness 4

The thickness is the distance between the solid's bottom and top.

An SVG is a sequence of geometric lines. When these lines are not straight, then points are interpolated along their trajectory. You can choose how many points to interpolate as so:

python svg2stl.py example.svg --definition 12

In addition to saving the result, you can show what the rendered solid looks like in a GUI:

python svg2stl.py example.svg --thickness 4 --show

Some SVGs have bogus instructions at the beginning of their path definition. For instance, the first shape of example_bogus.svg is bogus and cause the rendering to fail. Skipping it does the trick:

python svg2stl.py example_bogus.svg --skip 1

How it works

The SVG file is parsed into a sequence of steps thanks to svg.path.
Each step is turned into 2D geometric coordinates by sampling from each step's parametric equation with numpy.
Each coordinate is duplicated so that there are top and bottom coordinates.
The coordinates are stitched together to define panes: a floor, a ceiling, and many walls.
pygmsh does the heavy lifting. It generates a mesh of triangles from the panes through constrained Delaunay triangulation.

Motivation

There are some websites out there that already do this. Like this, this, and this. But they're websites, and sometimes it's nice to be able to do this from the command line. Especially if you want to process many SVGs.