DOI: 10.5061/dryad.m3s84
title: Data from: Unshackling evolution: evolving soft robots with multiple materials and a powerful generative encoding

description: In 1994 Karl Sims showed that computational evolution can produce
 interesting morphologies that resemble natural organisms. Despite nearly
 two decades of work since, evolved morphologies are not obviously more
 complex or natural, and the field seems to have hit a complexity ceiling.
 One hypothesis for the lack of increased complexity is that most work,
 including Sims', evolves morphologies composed of rigid elements,
 such as solid cubes and cylinders, limiting the design space. A second
 hypothesis is that the encodings of previous work have been overly
 regular, not allowing complex regularities with variation. Here we test
 both hypotheses by evolving soft robots with multiple materials and a
 powerful generative encoding called a compositional pattern-producing
 network (CPPN). Robots are selected for locomotion speed. We find that
 CPPNs evolve faster robots than a direct encoding and that the CPPN
 morphologies appear more natural. We also find that locomotion performance
 increases as more materials are added, that diversity of form and behavior
 can be increased with different cost functions without stifling
 performance, and that organisms can be evolved at different levels of
 resolution. These findings suggest the ability of generative soft-voxel
 systems to scale towards evolving a large diversity of complex, natural,
 multi-material creatures. Our results suggest that future work that
 combines the evolution of CPPN-encoded soft, multi-material robots with
 modern diversity-encouraging techniques could finally enable the creation
 of creatures far more complex and interesting than those produced by Sims
 nearly twenty years ago.
description: softbots2013ConfigHyperNEAT parameter file, HyperNEAT executable (usage: ./HyperNEAT -O [outputName] -I [parameterFileName] [optional: -R [random seed] -M [#ofMaterials] -P [penaltyType (key in parameter file)] -L [robotBoudingBoxLength]], Voxelize (usage: ./voxelyze -f [.vxa simulation file] [optional: -p (for print out during simulation)] - note: voxelize is not a GUI (VoxCAD is the GUI version, available online at www.voxcad.com - current for windows only)softbots2013Gen1000Fully evolved creatures (at generation 1000). Vxa files are to be imported as simulation into VoxCAD (available at voxcad.com) for viewing.softbots2013GenchampDataTxt data files describing the change over time for each evolutionary run. Data is formatted into the following columns: (1) generation number, (2) original fitness of most fit individual, (3) penalty adjusted fitness of most fit individual, (4) original fitness of population average, (5) penalty adjusted fitness of population averagesoftobts2013CodeREADMEFull source code for the project can be found at: http://jeffclune.com/codePublished/softbots2013Code.tgz Source code for voxelyze (non-GUI/library version of VoxCAD) can be found within: Voxel_Sim_noGui/Voxelyze Source code for CPPN-NEAT can be found within: hyperneat/HperNEAT_v2_5/HyperNEAT/Hypercube_NEAT/src/Experiments/HCUBE_SoftbotsExperiment.cpp Usages can be found in description of softobts2013Config.tgz