Elodin is a platform for rapid design, testing, and simulation of drones, satellites, and aerospace control systems.

Quick Demo: https://app.elodin.systems/sandbox/hn/cube-sat

Sandbox Alpha: https://app.elodin.systems
Docs (WIP): https://docs.elodin.systems

This repository is a collection of core libraries:

• libs/nox: Tensor library that compiles to XLA (like JAX, but for Rust).
• libs/nox-ecs: Rust ECS framework built to work with JAX and Nox, that allows you to build your own physics engine.
• libs/nox-py: Python version of nox-ecs, that works with JAX
• libs/nox-ecs-macros: Derive macros to generate implementations of ECS and Nox traits.
• libs/conduit: Column-based protocol for transferring ECS data between different systems.
• libs/xla-rs: Rust bindings to XLA's C++ API (originally based on https://github.com/LaurentMazare/xla-rs).

Join us on Discord: https://discord.gg/agvGJaZXy5!

1. Install Rust using https://rustup.rs
2. Setup a new venv with:

python3 -m venv .venv
 . .venv/bin/activate.fish # or activate.sh if you do not use fish

3. Install elodin, and matplotlib with

pip install libs/nox-py
pip install matplotlib

4. Try running the following code

import matplotlib.pyplot as plt
import jax.numpy as np
from elodin import *

@system
def gravity(q: Query[WorldPos]) -> Query[Force]:
  return q.map(Force, lambda _p: Force.from_linear(np.array([0.0, -9.81, 0.0])))

@system
def bounce(q: Query[WorldPos, WorldVel]) -> Query[WorldVel]:
  return q.map(WorldVel, lambda p, v: jax.lax.cond(
    jax.lax.max(p.linear()[1], v.linear()[1]) < 0.0,
    lambda _: WorldVel.from_linear(v.linear() * np.array([1.,-1.,1.]) * 0.85),
    lambda _: v,
    operand=None
  ))

w = WorldBuilder()
w.spawn(
    Body(
        world_pos=WorldPos.from_linear(np.array([0.0, 10.0, 0.0])),
        world_vel=WorldVel.from_linear(np.array([0.0, 0.0, 0.0])),
        inertia=Inertia.from_mass(1.0),
    )
)
client = Client.cpu()
exec = w.build(bounce.pipe(six_dof(1.0 / 60.0, gravity)))
t = range(500)
pos = []
for _ in t:
    exec.run(client)
    y = exec.column_array(Component.id(WorldPos))[0, 5]
    pos.append(y)
fig, ax = plt.subplots()
ax.plot(t, pos)
plt.show()

Licensed under either of

• Apache License, Version 2.0
• MIT License

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.