Vertexprint

Vertexprint is a tool for converting meshes into 3D printable assemblies. The tool takes a mesh as input and generates:

• STL files for vertex holders - printed components that hold rods in place.
• A table of edge lengths - cut your rods to these lengths, either by hand or with a laser cutter.

The generated assemblies use interference fits: vertex holders have slots that rods slide into. For complex parts, vertex pieces and edges can be labeled. Each slot on each vertex is labeled with the corresponding edge; use these slot numbers to determine which edges go where.

If you use a laser cutter to cut your rods, then vertexprint also generates SVG files to cut rods in batches.

Usage

Currently, vertexprint is a bare python script that generates openscad output to render. I intend to rewrite it in a more serious language, and offer a GUI so that non-programmers can easily use it.

# View all options
uv run python scripts/vertexprint.py --help

# Openscad preview a cube
uv run python scripts/vertexprint.py --file data/cube.obj

# Generate vertex pieces for a cube
uv run python scripts/vertexprint.py --file data/cube.obj --generate-outputs

# Generate a stanford bunny.
uv run python scripts/vertexprint.py \
    --file data/Bunny-LowPoly.stl \     # Vertexprint works on ordinary STL files too!
    --offset-type per_half_edge \       # Vertex pieces can have nonuniform offsets
    --radius 750 \                      # Rescale object such that the vertex furthest from the origin has this distance from the origin
    --rod-inset 6 \                     # Rods are inset by this distance
    --isotropize \                      # Make faces as equilateral as possible (avoids small angles) -- good if your vertex pieces come out wonky
    --label-vertices \                  # Add labels to vertex pieces
    --generate-outputs

David McCooey's website has a number of polyhedra definitions in a uniform text format. The data/ directory includes all Platonic, Archimedian, Catalan, and Kepler-Poinsot solids in this text format. I have written a simple utility to convert from this text format to a .obj format suitable for the main vertexprint program.

# View all options
uv run python scripts/convert_visual_polyhedra.py --help

# Convert a dodecahedron text file to .obj, then preview this dodecahedron
uv run python scripts/convert_visual_polyhedra.py data/dodecahedron.txt
uv run python scripts/vertexprint.py --file data/dodecahedron.obj

Installation & Development

This project uses Nix for environment management and uv for Python dependencies. You only need to have Nix installed to develop for this project. Nix manages everything else for you.

# Enter the development shell
nix develop

# Install dependencies with uv
uv sync

# Run tests
uv run pytest

If you don't want to use nix and uv, then you must install openscad from your system package manager. After that, install the dependencies listed out in pyproject.toml and run the vertexprint script normally.