Opossum—OPtimizatiOn Solver with SUrrogate Models
(by Opossum Support)
Opossum offers some of the best performing optimization algorithms in Grasshopper: model-based RBFOpt and RBFMOpt and evolutionary CMA-ES and NSGA-II.
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Opossum includes two of the best-performing,single-objective optimization algorithms in Grasshopper: model-based RBFOpt and evolutionary CMA-ES. It also includes the multi-objective RBFMOpt, and the multi-objective MACO (Ant Colony), MOEA/D, NSGA-II and NSPSO (Particle Swarm) algorithms from the Pygmo 2 library.

RBFOpt uses advanced machine learning techniques to find good solutions with a small number of function evaluations, i.e. simulations, while CMA-ES reliably finds near-optimal solutions when many function evaluations are possible. (Various papers with benchmark results are availabe here.) RBFMOpt won the “2-Objective Expensive” track of the international Black Box Optimization Competition 2019, surpassing the winner of the previous two years, the commercial algorithm Artelys Knitro.

Opossum 3 includes Performace Explorer, an interactive and intuitive visual tool for performance-informed design space exploration. Performance Explorer visualizes a single-objective optimization problem's fitness landscape with real-time performance feedback and interacts with Grasshopper to allow users to explore the corresponding designs. Papers on Performance Explorer are availabe here.

Opossum's GUI is similar to Galapagos. Opossum has a results table, which makes it easy to revisit all optimization results by double-clicking entries in the table.

Opossum requires a free license key, please email support to get one.

To get started, take a look at the video tutorials on Opossum and the Performance Explorer.

Opossum 3.0.0-beta as well as 1.5.0 and lower has been developed at the Advanced Architecture Lab with support from the SUTD-MIT International Design Centre.

Opossum is currently developed at ICD University Stuttgart.

Version History

Opossum 3.0.1       2022-August-10

  • Includes Performance Explorer

Opossum 2.2.5       2022-August-05

  • Fixed a bug where license had to be reentered after Rhino update
  • Minor bug fixes

Opossum 2.2.4       2021-April-07

  • Opossum does not expire the whole canvas anymore
  • "Tuned" default parameters for RBFMOpt

Opossum 2.2.3       2020-December-09

  • Fixed a bug with serialization in Grasshopper

Opossum 2.2.2       2020-December-01

  • Results table is more responsive
  • Results table is sortable
  • Fixed a bug where clicking the results table did not reset to the correct solution

Opossum 2.2.0       2020-October-15

  • Faster interaction with Python back-end
  • Added Paretorank and improved Hypervolume calculation for MOO results
  • Added tooltips for Expert settings
  • Added "augmented Tchebycheff sum", "epsilon", "Do Init?" options for RBFMOpt
  • Close now resets Opossum
  • Update to RBFOpt 4.2.1
  • Fixed Rhino 7 WIP display issue
  • Fixed crash when changing variables

Opossum 2.1.0        2020-May-23

  • Added multi-objective algorithms: MACO, MOEA/D and NSPSO.
  • Expert settings for all algorithms
  • Bug fixes

Opossum 2.0.0        2019-September-09

  • Multi-objective optimization with RBFMOpt and NSGA-II.

Opossum 1.7.1        2019-May-27

  • Genepools for CMAES starting point.

Opossum 1.7.0        2019-April-28

  • Includes CMA-ES algorithm
  • Eliminates need for installer (just drop Opossum.gha and the "Solvers" folder into Libraries)
  • Updated to RBFOpt 4.1.1: New options, more efficient initialization phase

Opossum 1.5.0        2018-March-16

  • Thread-safe
  • Canvas lockscreen
  • Automatic "max_evaluation" setting

Opossum 1.4.3        2017-Sept-30

  • Ensured Invariant Culture

Opossum 1.4.2        2017-Sep-23

  • Bug Fix

Opossum 1.4.1        2017-Sep-17

  • Update to RBFOpt 3.0.1: faster performance with improved local search
  • Results tab allows examination of all optimization results

Opossum 1.2.3        2017-Jun-06

  • Fixed bug caused by very long PATH variable

Opossum 1.2.2        2017-Jun-12

  • Fixed license write-permission issue

Opossum 1.2.1        2017-Jun-12

  • Updated to RBFOpt 2.1: faster performance
  • Included example file
  • Small bugfixes

Opossum 1.1.3        2017-Jun-12

  • Opossum window always on top.

Opossum 1.1.2        2017-Jun-12

  • More compact libraries
  • Culture-independent license check

Opossum 1.1.1        2016-Oct-27

  • GUI Improvements
  • Installer Improvements
  • Bug Fixes
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