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Staff Josua Sassen, M.Sc.

Mr. Sassen is now at ENS Paris-Saclay. This page is no longer maintained.

Contact Information

E-Mail: ed tod nnob-inu ta nessas tod ausoja tod b@foo tod de

My research is concerned with variational problems in geometry processing. Broadly speaking, I am interested in numerical methods for such problems arising from shape spaces and shape optimization. These typically find applications in computer graphics and geometric design. Recently, I have also become interested in using techniques from machine learning to tackle these problems. More details can be found on my personal website.


Summer semester 2023

Summer semester 2021

Summer semester 2019

See teaching activities of the whole group.

Completed Research Projects

Geodesic Paths in Shape Space

Project 5, FWF NFN S117.

Show description. Homepage.


  1. An elastic basis for spectral shape correspondence. F. Hartwig, J. Sassen, O. Azencot, M. Rumpf, and M. Ben-Chen. In ACM SIGGRAPH 2023 Conference Proceedings, SIGGRAPH '23. New York, NY, USA, 2023. Association for Computing Machinery. BibTeX Supplementary PDF DOI Code Teaser Talk
  2. Parametrizing Product Shape Manifolds by Composite Networks. J. Sassen, K. Hildebrandt, M. Rumpf, and B. Wirth. In International Conference on Learning Representations. 2023. BibTeX PDF arXiv OpenReview
  3. A pessimistic bilevel stochastic problem for elastic shape optimization. J. Burtscheidt, M. Claus, S. Conti, M. Rumpf, J. Sassen, and R. Schultz. Mathematical Programming, Nov 2021. BibTeX PDF DOI arXiv
  4. Association of reading performance in geographic atrophy secondary to age-related macular degeneration with visual function and structural biomarkers. S. H. Künzel, M. Lindner, J. Sassen, P. T. Möller, L. Goerdt, M. Schmid, S. Schmitz-Valckenberg, F. G. Holz, M. Fleckenstein, and M. Pfau. JAMA Ophthalmology, 139(11):1191–1199, 2021. BibTeX DOI
  5. A phase-field approach to variational hierarchical surface segmentation. J. Meny, M. Rumpf, and J. Sassen. Computer Aided Geometric Design, 89:102025, 2021. BibTeX PDF DOI
  6. Nonlinear Deformation Synthesis via Sparse Principal Geodesic Analysis. J. Sassen, K. Hildebrandt, and M. Rumpf. Comput. Graph. Forum, 39(5):119–132, 2020. BibTeX Video PDF DOI Talk
  7. Geometric optimization using nonlinear rotation-invariant coordinates. J. Sassen, B. Heeren, K. Hildebrandt, and M. Rumpf. Computer Aided Geometric Design, 77:101829, 2020. BibTeX DOI arXiv
  8. Discrete Gauß–Codazzi equations for efficient triangle mesh processing. J. Sassen. Master's Thesis, University of Bonn, 2019. BibTeX PDF