VecGL

VecGL is a 3D rendering engine with vector output. It is inspired by OpenGL with the key difference that the rendering result is a set of points, lines, and triangles - not a pixelated image. These geometric primitives can be used to generate vector graphics or to drive pen plotters.

Getting started

The VecGL package is available through pip.

$ python3 -m pip install vecgl

Let's create and render a simple model. Here's the complete example for a sphere.

from math import pi

from vecgl.export import write_svg
from vecgl.linalg import (get_frustum_mat4, get_rotate_x_mat4,
                          get_rotate_y_mat4, get_translate_mat4, mul_mat4)
from vecgl.modellib import get_sphere_model
from vecgl.rendering import render
from vecgl.viewer import show, show_interactively

# Get a predefined sphere model and choose nice colors.
# The sphere will span from -1.0 to 1.0 in all dimensions.
sphere = get_sphere_model(16, 32, "lightblue", "black")
simple_sphere = get_sphere_model(4, 8, "lightblue", "black")

# Look at the model interactively.
show_interactively(sphere, simple_model=simple_sphere)

# Define the view and the projection transforms.
view_mat4 = mul_mat4(
    get_translate_mat4(0.0, 0.0, -2.0),
    get_rotate_x_mat4(-0.2 * pi),
    get_rotate_y_mat4(0.15 * pi),
)
projection_mat4 = get_frustum_mat4(-1.0, 1.0, -1.0, 1.0, 1.0, 100.0)

# Transform our sphere model and bring it to the clip space.
transform_mat4 = mul_mat4(projection_mat4, view_mat4)
sphere_in_ndc = sphere.transform(transform_mat4)

# Render, display, and export the model.
rendered = render(sphere_in_ndc)
show(rendered)
write_svg(rendered, "sphere.svg")

# You can access the vector-based rendering result through the rendered model.
for ln in rendered.lines:
    print(ln)

VecGL will render and display the sphere and print the vector-based rendering result to stdout.

Build and run tests

Clone the repository.

$ git clone git@github.com:frgossen/vecgl.git
$ cd vecgl

Create a virtual environment and activate it (recommended).

$ python3 -m venv .venv
$ source .venv/bin/activate

Install the vecgl package in editable mode. This makes the package (and your changes) available when running the tests. Also, install the development dependencies, e.g. pytest to run the tests.

$ python3 -m pip install --editable .[lint,test,release]

You're all set for contributing back to the project. Run the tests with ...

$ python3 -m pytest --benchmark-skip

... and the benchmarks with ...

$ python3 -m pytest --benchmark-only