Object-oriented MATLAB API and Simulink blocks for 3D rigid-body physics.
PHX Toolbox allows you to build models from physical objects such as bodies with different shapes, joints, springs, ropes, force fields, or custom elements. The model is drawn directly into MATLAB axes and can be simulated immediately with one command. Simulation is powered by the Bullet physics engine, enhanced to allow co-simulation with custom MATLAB elements.
⚠️ Technical preview. PHX is published as a technical preview for evaluation and feedback. APIs may change between releases.
- Rigid-body dynamics with collisions and contacts (boxes, spheres, cylinders, cones, capsules, meshes, terrain, imported OBJ/STL, …)
- Joints (revolute, spherical, gear, …), springs and ropes
- Force and field elements (buoyancy, thrusters, resistance, dipole/monopole fields)
- Logging, tracing and measurement tools, interactive viewer
- Simulink block for closed-loop co-simulation
- Headless stepping for batch runs and experiments
PHX Toolbox also includes a set of AI skills for use with common AI agents. They are
installed with the toolbox in its skills folder (and live here in .claude/skills);
see AI agent skills in the User Guide for how to point your assistant at them.
- MATLAB R2025a or newer
- Simulink (only for the Simulink block)
- Windows, Linux, or macOS (prebuilt engine binaries are bundled for all three)
Download the latest PHXToolbox.mltbx from the
Releases page and double-click it in MATLAB (or use the
Add-On Manager). MATLAB installs the toolbox and adds it to the path.
clf; view(3); axis equal; grid on; camlight headlight;
phx.Body("Type", "static"); % ground
phx.Body("Position", [0.6 -0.5 2]); % a body that will fall onto it
sim = phx.Simulation;
sim.step(1, 100, 1); % simulate 1 s in 100 substeps, redrawingMore examples are in the examples/ folder (all named phxex_*), and
a guided introduction is in doc/GettingStarted.mlx.
PHX is a source-available technical preview, licensed under the PHX Preview
License (see LICENSE.txt). In short: you may read and adapt the
MATLAB (.m) source and use PHX for free, including commercially — but it is not
for sale and may not be used to build a competing product. The physics engine is
provided as a compiled binary.
PHX bundles the Bullet Physics engine under the zlib License; see
NOTICE.txt for attribution.
A separate commercial license will be available from HUMUSOFT s.r.o. for uses the Preview License does not permit. Contact us at phx@humusoft.cz.
During the technical preview we welcome bug reports and feedback via the issue
tracker, but we are not yet accepting external code contributions. See
CONTRIBUTING.md.
PHX is developed by HUMUSOFT s.r.o..