On the Efficiency of a Point Cloud Autoencoder as a Geometric Representation for Shape Optimization

A crucial step for optimizing a system is to formulate the objective function, and part of it concerns the selection of the design parameters. One of the major goals is to achieve a fair trade-off between exploring feasible solutions in the design space and maintaining admissible computational effort. In order to achieve such balance in optimization problems with Computer Aided Engineering (CAE) models, the conventional constructive geometric representations are substituted by deformation methods, e.g. free form deformation, where the position of a few control points might be capable of handling large scale shape modifications. In light of the recent developments in the field of geometric deep learning, autoencoders have risen as a promising alternative for efficiently condensing high-dimensional models into compact representations. In this paper, we present a novel perspective on geometric deep learning modelsby exploring the applicability of the latent space of a point cloud autoencoder in shape optimization problems with evolutionary algorithms. Focusing on engineering applications, a target shape matching optimization is used as a surrogate to the computationally expensive CAE simulations required in engineering optimizations. Through the quality assessment of the solutions achieved in the optimization and further aspects, such as shape feasibility, point cloud autoencoders showed to be consistent and suitable geometric representations for such problems, adding a new perspective on the approaches for handling high-dimensional models to optimization tasks.

[1]  Stefan Menzel,et al.  On Shape Deformation Techniques for Simulation-Based Design Optimization , 2015 .

[2]  Leonidas J. Guibas,et al.  PointNet: Deep Learning on Point Sets for 3D Classification and Segmentation , 2016, 2017 IEEE Conference on Computer Vision and Pattern Recognition (CVPR).

[3]  Leonidas J. Guibas,et al.  ShapeNet: An Information-Rich 3D Model Repository , 2015, ArXiv.

[4]  M. Olhofer,et al.  Evolutionary Optimisation of an Exhaust Flow Element with Free Form Deformation , 2009 .

[5]  C. Segura,et al.  Constructive Solid Geometry Using BSP Tree , 2013 .

[6]  Dong Tian,et al.  FoldingNet: Interpretable Unsupervised Learning on 3D Point Clouds , 2017, ArXiv.

[7]  Yu Zhang,et al.  Multi-round Surrogate-based Optimization for Benchmark Aerodynamic Design Problems , 2016 .

[8]  Joaquim R. R. A. Martins,et al.  A CAD-Free Approach to High-Fidelity Aerostructural Optimization , 2010 .

[9]  Nikolaus Hansen,et al.  The CMA Evolution Strategy: A Comparing Review , 2006, Towards a New Evolutionary Computation.

[10]  Andy J. Keane,et al.  Dimension Reduction for Aerodynamic Design Optimization , 2011 .

[11]  Michael J. Black,et al.  Generating 3D faces using Convolutional Mesh Autoencoders , 2018, ECCV.

[12]  Leonidas J. Guibas,et al.  PointNet++: Deep Hierarchical Feature Learning on Point Sets in a Metric Space , 2017, NIPS.

[13]  Xin Yao,et al.  Target shape design optimization by evolving splines , 2007, 2007 IEEE Congress on Evolutionary Computation.

[14]  C. Dapogny,et al.  An optimization method for elastic shape matching , 2016 .

[15]  Pierre Vandergheynst,et al.  Geometric Deep Learning: Going beyond Euclidean data , 2016, IEEE Signal Process. Mag..

[16]  Monique Nahas,et al.  Animation of a B-Spline figure , 1988, The Visual Computer.

[17]  A Samareh Jamshid,et al.  A Survey of Shape Parameterization Techniques , 1999 .

[18]  Leonidas J. Guibas,et al.  Learning Representations and Generative Models for 3D Point Clouds , 2017, ICML.

[19]  Hossein Zare-Behtash,et al.  State-of-the-art in aerodynamic shape optimisation methods , 2018, Appl. Soft Comput..

[20]  Leonidas J. Guibas,et al.  Representation Learning and Adversarial Generation of 3D Point Clouds , 2017, ArXiv.

[21]  Michael I. Friswell,et al.  Aerodynamic optimisation of a camber morphing aerofoil , 2015 .

[22]  Bernhard Sendhoff,et al.  Representing the Change - Free Form Deformation for Evolutionary Design Optimization , 2008, Evolutionary Computation in Practice.

[23]  Josef Hoschek,et al.  Handbook of Computer Aided Geometric Design , 2002 .

[24]  Fabrizio Nicolosi,et al.  Aerodynamic guidelines in the design and optimization of new regional turboprop aircraft , 2014 .

[25]  Jimmy Ba,et al.  Adam: A Method for Stochastic Optimization , 2014, ICLR.

[26]  Thomas Bäck,et al.  A Survey of Evolution Strategies , 1991, ICGA.

[27]  M. Olhofer,et al.  Application of Free Form Deformation Techniques in Evolutionary Design Optimisation , 2005 .

[28]  Alexander M. Bronstein,et al.  Deformable Shape Completion with Graph Convolutional Autoencoders , 2017, 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition.

[29]  Dong Tian,et al.  FoldingNet: Point Cloud Auto-Encoder via Deep Grid Deformation , 2017, 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition.

[30]  Jasbir S. Arora Chapter 2 – Optimum Design Problem Formulation , 2017 .

[31]  Thomas Bäck,et al.  An Overview of Evolutionary Algorithms for Parameter Optimization , 1993, Evolutionary Computation.

[32]  Gerald Farin Chapter 10 – B-splines , 1993 .

[33]  Thomas W. Sederberg,et al.  Free-form deformation of solid geometric models , 1986, SIGGRAPH.