252-0538-00, Spring 2017 Modeling and Processing

Introduction and Overview

February 21, 2018 Course Staff

Lecturers

Prof. Stelian Coros Dr. Roi Poranne stelian.coros@inf roi.poranne@inf CNB, H 101 CNB, E 106

Assistants

Moritz Geilinger Michael Rabinovich moritz.geilinger@inf michael.rabinovich@inf CNB, E 108.1 CAB G 82.2

http://crl.ethz.ch/teaching/shape-modeling-18/

February 21, 2018 Roi Poranne # 2 CRL – Computational Robotics Lab

Stelian Coros Roi Poranne David Hahn James Bern Vittorio Megaro

Moritz Geilinger Nitish Kumar Simon Duenser Simon Zimmerman

February 21, 2018 Roi Poranne # 3 IGL – Interactive Geometry Lab

Faculty PhD students Postdocs

Christian Schüller Oliver Glauser Roi Poranne

Olga Sorkine-Hornung

Michael Rabinovich Yifan Wang

February 21, 2018 Roi Poranne # 4 What is this course about?

Shape modeling

February 21, 2018 Roi Poranne # 5 What is this course about?

Geometry processing

Signal processing on surfaces

Levy and Zhang, Spectral Mesh Processing, Siggraph Asia 2009 course notes

February 21, 2018 Roi Poranne # 6 What is this course about?

Spherical cow in vacuum https://en.wikipedia.org/wiki/Spherical_cow Geometry processing

Crane et al. Conformal Willmore Flow, Siggraph 2013

February 21, 2018 Roi Poranne # 7 What is this course about?

Computational fabrication

February 21, 2018 Roi Poranne # 8 What is this course about?

Computational fabrication

February 21, 2018 Roi Poranne # 9 Course Goals

Shape Computational Geometry modeling fabrication processing

Theory and Modeling Hands-on applications competition experience

February 21, 2018 Roi Poranne # 10 Geometry = Shape = Object = Model

February 21, 2018 Roi Poranne # 11 Applications

Product design and prototyping Medicine, prosthetics

Architecture Cultural heritage

February 21, 2018 Roi Poranne # 12 Applications

Geographical systems Manufacturing, 3D Printing

Boyer et al. 2012 Biology Animation

February 21, 2018 Roi Poranne # 13 Fabrication

February 21, 2018 Roi Poranne # 14 Digital Geometry Processing

● DGP! ● Processing of discrete (polygonal mesh) models ● Why discrete? ▪ Simplicity ▪ Efficiency ▪ Output of most scanners ▪ Input to most simulators

February 21, 2018 Roi Poranne # 15 Interactive Shape Modeling

● Tools for design, editing and animation of digital ▪ Interactive = fast ▪ Intuitive = predictable

http://youtu.be/EMx6yNe23ug

February 21, 2018 Roi Poranne # 16 Interactive Shape Modeling Modeling is difficult!

https://youtu.be/ALbt17LLH54

February 21, 2018 Roi Poranne # 17 Interactive Shape Modeling Modeling is difficult!

February 21, 2018 Roi Poranne # 18 Interactive Shape Modeling Modeling is difficult!

Hope: computation can compensate

February 21, 2018 Roi Poranne # 19 Interactive Shape Modeling Modeling is easy?

https://youtu.be/nUe2IHN_isU February 21, 2018 Roi Poranne # 20 Tools of the trade

● Use techniques from both CS & Math ▪ Numerical Optimization ▪ Discrete differential geometry ▪ Linear algebra ▪ Graph theory ▪ ... ● Coding!

February 21, 2018 Roi Poranne # 21 Organization

● Communication through course website: http://crl.ethz.ch/teaching/shape-modeling-18/ ● Mailing list ● Weekly lectures and exercise sessions

● Prerequisites: ▪ Intro to or Computer Graphics (252-0543-01L) – somewhat soft condition ▪ Knowledge of C++ programming – firm condition

February 21, 2018 Roi Poranne # 22 Course Materials

● No book covers all topics ▪ Many of the topics are recent research results ▪ The following book might be helpful: Processing, Mario Botsch, Leif Kobbelt, Mark Pauly, Pierre Alliez, Bruno Levy, AK Peters, 2010. http://www.pmp-book.org/ Several copies available in the CS library.

● We will link to some relevant papers in the course slides ● Lecture slides available on the website shortly after the class

● Papers from: ACM SIGGRAPH, Symposium on Geometry Processing (SGP), Shape Modeling International (SMI), EUROGRAPHICS, see http://kesen.huang.googlepages.com/

February 21, 2018 Roi Poranne # 23 Grading

● Homework assignments 80% ▪ Basic mesh modeling 10% ▪ reconstruction 14% ▪ Parameterization 14% ▪ Mesh deformation 14% ▪ Finite Element Method 14% ▪ Geometry Optimization 14%

● Exam (last tutorial of semester) – 20%

February 21, 2018 Roi Poranne # 24 Policy

● Homework assignments to be done individually. You may consult but may not collaborate. More details in the exercise section.

● Assignment are evaluated mostly based on a written report. This report should be GOOD.

February 21, 2018 Roi Poranne # 25 Course Topics

Shape representation Digital geometry processing Shape acquisition 3D printing Finite element method Surface parameterization Discrete differential geometry Shape optimization Editing and modeling Architectural geometry optimization Digital fabrication

February 21, 2018 Roi Poranne # 26 Shape representation

A little about Parametric curves/surfaces Implicits

February 21, 2018 Roi Poranne # 27 Shape representation

But mostly about Polygonal meshes

February 21, 2018 Roi Poranne # 28 Shape acquisition

Scanning

February 21, 2018 Roi Poranne # 29 Shape acquisition

Reconstruction

“Reconstruction and representation of 3D objects with radial basis functions”, Carr et al., ACM SIGGRAPH 2001

February 21, 2018 Roi Poranne # 30 Course Topics

Differential geometry Continuous and discrete Powerful tool to analyze and model shapes

February 21, 2018 Roi Poranne # 31 Course Topics

Digital geometry processing Denoising, smoothing, simplification, remeshing, parameterization, compression

February 21, 2018 Roi Poranne # 32 Course Topics

Parameterization

3D space (푥, 푦, 푧) 2D parameter domain (푢, 푣)

February 21, 2018 Roi Poranne # 33 Course Topics

Parameterization

February 21, 2018 Roi Poranne # 34 Course Topics

Shape creation and editing

February 21, 2018 Roi Poranne # 35 Course Topics

Shape creation and editing

February 21, 2018 Roi Poranne # 36 Course Topics

Shape creation and editing

February 21, 2018 Roi Poranne # 37 Course Topics

Animation

http://youtu.be/P9fqm8vgdB8

http://youtu.be/Pjg33pH9RKo http://www.mit.edu/~ibaran/autorig/

February 21, 2018 Roi Poranne # 38 Course Topics

Shape optimization

input optimized result (carved volume)

http://igl.ethz.ch/projects/spin-it/ “Spin-It: Optimizing Moment of Inertia for Spinnable Objects”, Bächer et al., ACM SIGGRAPH 2014

February 21, 2018 Roi Poranne # 39 Course Topics

Shape optimization

Bharaj et al., "Computational design of metallophone contact sounds”, Siggraph 2014

February 21, 2018 Roi Poranne # 40 Course Topics

Topology optimization

Lu et al., Siggraph 2014 Stava et al., Siggraph 2012Wang et al., Siggraph Asia 2013

February 21, 2018 Roi Poranne # Course Topics

Topology optimization

February 21, 2018 Roi Poranne #