Cushion: Soft Robotics Simulation in Grasshopper, Powered by SOFA

Open-source Grasshopper plugin that runs SOFA soft-body FEM directly from parametric models. Define a body, its cavities or tendons, and an actuation schedule, and get trajectories, forces, and deformed shapes back on the canvas.

📄 GitHub • Zenodo DOI 10.5281/zenodo.21625292

Overview

Cushion is the soft layer between Grasshopper and SOFA. You describe a soft robot the way you already model in Rhino/Grasshopper: a deformable body, the pneumatic cavities or tendons that drive it, and a schedule of pressures or pulls over time. Cushion meshes the geometry, writes a runnable SOFA scene, launches the simulation, and brings the results (trajectories, forces, contacts, deformed shapes) back onto the canvas.

The scene structure follows the Monolithic Units pipeline (RoboSoft 2026): corotational tetrahedral FEM, a homogenized lattice material, MeshROI-based local stiffening, and SoftRobots pressure and cable constraints.

Highlights

  • v0.1.0 released July 2026: open source (LGPL-2.1), archived on Zenodo
  • Available on food4Rhino and Rhino’s Package Manager
  • Worked examples: PneuNet gripper and tendon-driven continuum robot
  • Invited talk at SOFA Week 2026 (Nov 25–27, Lille)

Tendon continuum robot

Developed with Anderson B. Nardin (Soft BioRobotics Perception, IIT).

Citation

Exley, T., Nardin, A. B.
Cushion: a Grasshopper plugin for soft-robotics simulation powered by SOFA (v0.1.0).
Zenodo, 2026. doi:10.5281/zenodo.21625292