AAL presented Opossum, an optimization tool for Grasshopper based on the RBFOpt library, at a two-day workshop at the Advanced Architectural Geometry 2016 Conference at the ETH Zurich, Switzerland on 9 and 10 of September. The workshop -called “Optimize this!”- was proposed and directed by Thomas Wortmann with the assistance of Aloysius Lian and Dimitry Demin from AAL.

The workshop had thirteen participants -one more than the planned maximum number. All participants had a background in architecture, with four professional architects -one working for a climate and one for an underground engineering firm-, five PhD students, three master students and one researcher.

The workshop consisted of brief lectures and hands-on sessions. The lectures introduced global, black-box optimization, discussed the differences between such optimization methods. They also provided an overview over related topics, such a multi-objective optimization and multi-variate visualization.

In the hands-on sessions, participants created their own optimization problems in Grasshopper, using plug-ins for structural (Karamba), energy (Archsim) and daylighting (Diva) simulations. The problems reflected the participants interested and practice and covered the optimization of building designs in terms of structure, energy consumption and view quality, the optimization of an urban design in terms of daylight, and the optimization of frame works used for constructing tunnels.

Using these problems, the participants compared the performance of five optimization tools available in Grasshopper, including Opossum. The remaining optimization tools were “Galapagos”, which includes a genetic algorithm and simulated annealing, “Goat”, which includes direct search and controlled random search, Silvereye, which is a particle swarm, and Octopus, which is a multi-objective, genetic algorithm.