(by Mathias Bernhard)
Volumetric Modeling with signed distance functions (SDF) for Grasshopper.
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AXOLOTL provides a set of components for volumetric modeling in Rhino Grasshopper. They work based on the principle of signed distance functions (SDF). In boundary representations (BRep), objects are defined by vertices connected by edges and faces. In function representations (FRep), objects are defined by a function f that maps any point (x,y,z) to a real value d, the distance to the objects: f(x,y,z)=d

The components are organized in groups. A typical workflow is to choose objects from PRIMITIVES, combine them using e.g. Boolean operations from COMBINATIONS, add further MODIFICATIONS as necessary and finally visualize the distance object using a component from the MESHING tab. Furthermore, there are different kinds of LATTICES, some MATH functions, components to convert Rhino GEOMETRY into an SDF and some utilities to ANALYSE the SDF.


  • Download and unpack the zip-Archive
  • There will be two files, a hidden file starting with ._ You only need the other file, Axolotl.gha
  • unblock the Axolotl.gha file
  • open the components folder: In Grasshopper go to File > Special Folders > Components Folder
  • copy the file Axolotl.gha in there
  • you might need to restart Rhino


Check the component overview and description page here: (Thanks, Robin Fernandes!)


Example definitions showing the use of the AXOLOTL components can be found in the download section. (Thanks, Rémy Clemente!)

Join the AXOLOTL group on to see some examples and share your creations.

Keywords: volumetric modeling, signed distance function (SDF), voxel space, function representation (FRep), constructive solid geometry (CSG), implicit surface


More about the research on volumetric modeling can be found here:

We wrote a paper about many of the concepts involved, called Volumetric Modelling for 3D Printed Architecture. Please consider citing it, if you find Axolotl useful. Thank you :)

An older (Python) version of the components can be found here:


Mathias Bernhard (PSL) and Benjamin Dillenburger (DBT)
PSL - Polyhedral Structures Laboratory / Weitzman School of Design / University of Pennsylvania
DBT - Digital Building Technologies / Institute of Technology in Architecture / ETH Zurich
Mathias Bernhard / / github: worbit