Libra is a computational tool available in Rhinoceros’ 3D parametric platform of Grasshopper to generate structural topologies. It introduces a novel design workflow that supports decision making through rules that construct transformation policies. Libra, with the help of policies, describes an incremental transformative process that allows the transition from an incomplete network to a complete one. The networks represent structural topologies that suggest indicative force flows and assist the design space exploration through structurally valid design candidates.

Banner Libra

Download & Installation

The plugin operates in the parametric environment of Grasshopper within Rhinoceros 3D, a 3D modeling software widely used in architecture and structural design firms. The plugin is available via the PackageManager of Rhinoceros 3D. It is also available for download on Food4Rhino.


  1. In Rhino 7, run the PackageManager command.
  2. Look for “Libra”.
  3. Click install.
  4. Restart Rhino to load the plugin.


Libra aims at the transition from an incomplete network (stage 00) to a complete one (stage 13) through incremental transformations. In other words, the incremental elimination of interim forces in the network. At every intermediate step the network is in static equilibrium (interim when interim forces—vectors in cyan—are still present, or global when no interim forces exist).

The transformations are ruled by a policy that expresses the design decisions in a descriptive way and integrate static equilibrium. Therefore, the generated networks satisfy static equilibrium.


How to reference the tool

Please use the full reference given here.

About the author

Libra has been developed by Ioannis Mirtsopoulos as part of his doctoral research at Structural Xploration Lab (SXL) at EPFL in Switzerland.

Related publications

  • Exploration of static equilibrium representations; policies and genetic algorithms
    Structures and Architecture, 2022 (detailed record)
  • Grammar-based generation of bar networks in static equilibrium with bounded bar lengths
    IASS Symposium, 2020 (detailed record)
  • Design space exploration through force-based grammar rule
    archiDOCT, 2020 (detailed record)