---
OA_place: publisher
OA_type: hybrid
_id: '22129'
abstract:
- lang: eng
  text: "Inside–outside classification is widely used for geometry processing tasks
    such as surface reconstruction, geometry completion,\r\nand calculating signed
    distance fields. We introduce a new integral formulation of this problem, which
    assigns confidence\r\nscores that points are inside or outside, given incomplete
    boundary geometry. Even though our geometric construction does\r\nnot appear in
    previous work, we show that it is unexpectedly linked to both the well-established
    generalized winding number\r\n(GWN) and pseudonormal methods for geometry completion,
    and it provably reduces to either one of them for specific values\r\nof a control
    parameter. The results obtained with our method frequently outperform screened
    Poisson surface reconstruction\r\n(PSR), GWN, and the pseudonormal method in terms
    of quality, and are at least on par with them on all of our examples. Unlike\r\nthese
    methods, our algorithm naturally extends to the multi-label setting, in which
    regions with an arbitrary number of colors\r\nor physical materials can be reconstructed,
    and non-manifold features such as T-junctions may appear in the interface and\r\nboundary
    geometry"
article_processing_charge: No
author:
- first_name: 'Ziyu '
  full_name: 'Wei, Ziyu '
  last_name: Wei
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Aleksei
  full_name: Kalinov, Aleksei
  id: 44b7120e-eb97-11eb-a6c2-e1557aa81d02
  last_name: Kalinov
  orcid: 0000-0003-2189-3904
- first_name: Peter
  full_name: Synak, Peter
  id: 331776E2-F248-11E8-B48F-1D18A9856A87
  last_name: Synak
- first_name: Christopher J
  full_name: Wojtan, Christopher J
  id: 3C61F1D2-F248-11E8-B48F-1D18A9856A87
  last_name: Wojtan
  orcid: 0000-0001-6646-5546
citation:
  ama: 'Wei Z, Hafner C, Kalinov A, Synak P, Wojtan C. Circles of confidence for multi-label
    geometry completion. In: <i>Computer Graphics Forum</i>. Vol 45. Wiley. doi:<a
    href="https://doi.org/10.1111/cgf.70516">10.1111/cgf.70516</a>'
  apa: 'Wei, Z., Hafner, C., Kalinov, A., Synak, P., &#38; Wojtan, C. (n.d.). Circles
    of confidence for multi-label geometry completion. In <i>Computer Graphics Forum</i>
    (Vol. 45). Bern, Switzerland: Wiley. <a href="https://doi.org/10.1111/cgf.70516">https://doi.org/10.1111/cgf.70516</a>'
  chicago: Wei, Ziyu , Christian Hafner, Aleksei Kalinov, Peter Synak, and Chris Wojtan.
    “Circles of Confidence for Multi-Label Geometry Completion.” In <i>Computer Graphics
    Forum</i>, Vol. 45. Wiley, n.d. <a href="https://doi.org/10.1111/cgf.70516">https://doi.org/10.1111/cgf.70516</a>.
  ieee: Z. Wei, C. Hafner, A. Kalinov, P. Synak, and C. Wojtan, “Circles of confidence
    for multi-label geometry completion,” in <i>Computer Graphics Forum</i>, Bern,
    Switzerland, vol. 45, no. 5.
  ista: 'Wei Z, Hafner C, Kalinov A, Synak P, Wojtan C. Circles of confidence for
    multi-label geometry completion. Computer Graphics Forum. Eurographics: Symposium
    on Geometry Processing vol. 45.'
  mla: Wei, Ziyu, et al. “Circles of Confidence for Multi-Label Geometry Completion.”
    <i>Computer Graphics Forum</i>, vol. 45, no. 5, Wiley, doi:<a href="https://doi.org/10.1111/cgf.70516">10.1111/cgf.70516</a>.
  short: Z. Wei, C. Hafner, A. Kalinov, P. Synak, C. Wojtan, in:, Computer Graphics
    Forum, Wiley, n.d.
conference:
  end_date: 2026-07-03
  location: Bern, Switzerland
  name: 'Eurographics: Symposium on Geometry Processing'
  start_date: 2026-07-01
corr_author: '1'
date_created: 2026-06-23T09:08:41Z
date_published: 2026-06-24T00:00:00Z
date_updated: 2026-06-24T05:49:08Z
day: '24'
ddc:
- '005'
department:
- _id: ChWo
- _id: GradSch
doi: 10.1111/cgf.70516
file:
- access_level: open_access
  checksum: 365f986db34e3fbce74089207599253b
  content_type: application/pdf
  creator: mly
  date_created: 2026-06-23T09:07:22Z
  date_updated: 2026-06-23T09:07:22Z
  file_id: '22132'
  file_name: document(3).pdf
  file_size: 14536575
  relation: main_file
  success: 1
file_date_updated: 2026-06-23T09:07:22Z
has_accepted_license: '1'
intvolume: '        45'
issue: '5'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '06'
oa: 1
oa_version: Published Version
project:
- _id: 34bc2376-11ca-11ed-8bc3-9a3b3961a088
  grant_number: '101045083'
  name: Computational Discovery of Numerical Algorithms for Animation and Simulation
    of Natural Phenomena
publication: Computer Graphics Forum
publication_status: accepted
publisher: Wiley
quality_controlled: '1'
status: public
title: Circles of confidence for multi-label geometry completion
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 45
year: '2026'
...
---
OA_place: publisher
OA_type: hybrid
_id: '21923'
abstract:
- lang: eng
  text: "The appearance of simulated natural phenomena heavily depends on the way
    surfaces are textured. However, applying texture maps to dynamic deformable surfaces
    presents a significant challenge, due to ever-shifting differences in length scales
    involved. When these surfaces move and advect the texture along with them, their
    final appearance degrades as deformed regions dramatically distort their texture
    map. Modifications to the texture directly at the pixel level in response to the
    deformation may introduce ghosting artifacts and look unnatural. In the real world,
    the appearance of surface details on a deforming material changes through the
    interplay of physical processes such as rupturing, exposure of internal structure,
    or wrinkling. Motivated by these behaviors, in this work we explore how physical
    principles can guide the texturing methods based on the measure of surface deformation.\r\nWe
    present two novel wave-based procedural texturing algorithms which reproduce common
    physical properties like advection and self-similarity, enabling the plausible
    animation of deforming objects with extreme texture map distortions. Our algorithms
    are fully procedural, require no actual physics simulation, and store no state
    or history of deformation besides the input UV map, making them highly parallelizable
    on the GPU and efficient enough for real-time applications. We show the versatility
    of the method by animating physical phenomena with extreme deformations such as
    flowing lava, stretching putty and outpouring sludge."
acknowledged_ssus:
- _id: ScienComp
acknowledgement: "We thank the anonymous reviewers for their helpful comments, the
  members of the Visual Computing Group at ISTA for their feedback. We also thank
  Jonathan Gagnon for their help with running the Lapped Textures codes and SideFX
  for the Houdini Education software licenses.\r\nImages in Fig. 2 by Kisoulou and
  Vultured on Unsplash, Michal Jarmoluk and Public Domain Pictures from Pixabay and
  Hawai‘i Volcanoes NPS on flickr. This research was supported by the Scientific Service
  Units (SSU) of ISTA through resources provided by Scientific Computing and was funded
  in part by the European Union (ERC-2021-COG 101045083 CoDiNA)."
article_number: '154'
article_processing_charge: Yes
article_type: original
author:
- first_name: Aleksei
  full_name: Kalinov, Aleksei
  id: 44b7120e-eb97-11eb-a6c2-e1557aa81d02
  last_name: Kalinov
  orcid: 0000-0003-2189-3904
- first_name: Mickaël
  full_name: Ly, Mickaël
  id: 6340d7f0-b48d-11eb-b10d-b7487e71d9f1
  last_name: Ly
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Christopher J
  full_name: Wojtan, Christopher J
  id: 3C61F1D2-F248-11E8-B48F-1D18A9856A87
  last_name: Wojtan
  orcid: 0000-0001-6646-5546
citation:
  ama: Kalinov A, Ly M, Hafner C, Wojtan C. Physics-inspired procedural texturing
    of extremely deformable surfaces. <i>ACM Transactions on Graphics</i>. 45(4).
    doi:<a href="https://doi.org/10.1145/3811353">10.1145/3811353</a>
  apa: 'Kalinov, A., Ly, M., Hafner, C., &#38; Wojtan, C. (n.d.). Physics-inspired
    procedural texturing of extremely deformable surfaces. <i>ACM Transactions on
    Graphics</i>. Los Angeles, CA, United States: ACM. <a href="https://doi.org/10.1145/3811353">https://doi.org/10.1145/3811353</a>'
  chicago: Kalinov, Aleksei, Mickaël Ly, Christian Hafner, and Chris Wojtan. “Physics-Inspired
    Procedural Texturing of Extremely Deformable Surfaces.” <i>ACM Transactions on
    Graphics</i>. ACM, n.d. <a href="https://doi.org/10.1145/3811353">https://doi.org/10.1145/3811353</a>.
  ieee: A. Kalinov, M. Ly, C. Hafner, and C. Wojtan, “Physics-inspired procedural
    texturing of extremely deformable surfaces,” <i>ACM Transactions on Graphics</i>,
    vol. 45, no. 4. ACM.
  ista: Kalinov A, Ly M, Hafner C, Wojtan C. Physics-inspired procedural texturing
    of extremely deformable surfaces. ACM Transactions on Graphics. 45(4), 154.
  mla: Kalinov, Aleksei, et al. “Physics-Inspired Procedural Texturing of Extremely
    Deformable Surfaces.” <i>ACM Transactions on Graphics</i>, vol. 45, no. 4, 154,
    ACM, doi:<a href="https://doi.org/10.1145/3811353">10.1145/3811353</a>.
  short: A. Kalinov, M. Ly, C. Hafner, C. Wojtan, ACM Transactions on Graphics 45
    (n.d.).
conference:
  end_date: 2026-07-23
  location: Los Angeles, CA, United States
  name: 'SIGGRAPH: International Conference and Exhibition on Computer Graphics and
    Interactive Techniques'
  start_date: 2026-07-19
corr_author: '1'
date_created: 2026-05-29T13:25:16Z
date_published: 2026-07-01T00:00:00Z
date_updated: 2026-06-02T08:56:50Z
day: '01'
ddc:
- '006'
department:
- _id: GradSch
- _id: ChWo
doi: 10.1145/3811353
file:
- access_level: open_access
  checksum: ea165bf731ddd3045f83878dcb833672
  content_type: video/mp4
  creator: akalinov
  date_created: 2026-05-29T13:19:33Z
  date_updated: 2026-05-29T13:19:33Z
  file_id: '21924'
  file_name: tog454-article154-supplemental.mp4
  file_size: 77337231
  relation: main_file
  success: 1
- access_level: open_access
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  content_type: video/mp4
  creator: akalinov
  date_created: 2026-05-29T13:19:37Z
  date_updated: 2026-05-29T13:19:37Z
  file_id: '21925'
  file_name: tog454-article154-video.mp4
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  success: 1
- access_level: open_access
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  content_type: application/pdf
  creator: akalinov
  date_created: 2026-05-29T13:19:33Z
  date_updated: 2026-05-29T13:19:33Z
  file_id: '21926'
  file_name: tog454-article154-supplemental.pdf
  file_size: 6793867
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  success: 1
- access_level: open_access
  checksum: 51bc60d2de867fbfa570652dec7993b4
  content_type: application/pdf
  creator: akalinov
  date_created: 2026-05-29T13:19:36Z
  date_updated: 2026-05-29T13:19:36Z
  file_id: '21927'
  file_name: tog454-article154-main-1.pdf
  file_size: 84173392
  relation: main_file
  success: 1
file_date_updated: 2026-05-29T13:19:37Z
has_accepted_license: '1'
intvolume: '        45'
issue: '4'
keyword:
- Procedural animation
language:
- iso: eng
month: '07'
oa: 1
oa_version: Accepted Version
project:
- _id: 34bc2376-11ca-11ed-8bc3-9a3b3961a088
  grant_number: '101045083'
  name: Computational Discovery of Numerical Algorithms for Animation and Simulation
    of Natural Phenomena
publication: ACM Transactions on Graphics
publication_identifier:
  issn:
  - 0730-0301
publication_status: inpress
publisher: ACM
quality_controlled: '1'
status: public
title: Physics-inspired procedural texturing of extremely deformable surfaces
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 45
year: '2026'
...
---
_id: '17203'
abstract:
- lang: eng
  text: "The behavior of a rigid body primarily depends on its mass moments, which
    consist of the mass, center of mass, and moments of inertia. It is possible to
    manipulate these quantities without altering the geometric appearance of an object
    by introducing cavities in its interior. Algorithms that find cavities of suitable
    shapes and sizes have enabled the computational design of spinning tops, yo-yos,
    wheels, buoys, and statically balanced objects. Previous work is based, for example,
    on topology optimization on voxel grids, which introduces a large number of optimization
    variables and box constraints, or offset surface computation, which cannot guarantee
    that solutions to a feasible problem will always be found.\r\n\r\nIn this work,
    we provide a mathematical analysis of constrained topology optimization problems
    that depend only on mass moments. This class of problems covers, among others,
    all applications mentioned above. Our main result is to show that no matter the
    outer shape of the rigid body to be optimized or the optimization objective and
    constraints considered, the optimal solution always features a quadric-shaped
    interface between material and cavities. This proves that optimal interfaces are
    always ellipsoids, hyperboloids, paraboloids, or one of a few degenerate cases,
    such as planes.\r\n\r\nThis insight lets us replace a difficult topology optimization
    problem with a provably equivalent non-linear equation system in a small number
    (<10) of variables, which represent the coefficients of the quadric. This system
    can be solved in a few seconds for most examples, provides insights into the geometric
    structure of many specific applications, and lets us describe their solution properties.
    Finally, our method integrates seamlessly into modern fabrication workflows because
    our solutions are analytical surfaces that are native to the CAD domain."
acknowledgement: We thank Gianmarco Cherchi for his help in tailoring the Mesh Booleans
  code for this project, Stefan Jeschke for his help with the photographs, Malina
  Strugaru and Aleksei Kalinov for their help with the samples, and the anonymous
  reviewers as well as the members of the ISTA Visual Computing Group for their feedback.
  This project was funded in part by the European Research Council (ERC Consolidator
  Grant 101045083 CoDiNA).
article_number: '78'
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Mickaël
  full_name: Ly, Mickaël
  id: 6340d7f0-b48d-11eb-b10d-b7487e71d9f1
  last_name: Ly
- first_name: Christopher J
  full_name: Wojtan, Christopher J
  id: 3C61F1D2-F248-11E8-B48F-1D18A9856A87
  last_name: Wojtan
  orcid: 0000-0001-6646-5546
citation:
  ama: 'Hafner C, Ly M, Wojtan C. Spin-it faster: Quadrics solve all topology optimization
    problems that depend only on mass moments. <i>Transactions on Graphics</i>. 2024;43(4).
    doi:<a href="https://doi.org/10.1145/3658194">10.1145/3658194</a>'
  apa: 'Hafner, C., Ly, M., &#38; Wojtan, C. (2024). Spin-it faster: Quadrics solve
    all topology optimization problems that depend only on mass moments. <i>Transactions
    on Graphics</i>. Denver, Colorado: Association for Computing Machinery. <a href="https://doi.org/10.1145/3658194">https://doi.org/10.1145/3658194</a>'
  chicago: 'Hafner, Christian, Mickaël Ly, and Chris Wojtan. “Spin-It Faster: Quadrics
    Solve All Topology Optimization Problems That Depend Only on Mass Moments.” <i>Transactions
    on Graphics</i>. Association for Computing Machinery, 2024. <a href="https://doi.org/10.1145/3658194">https://doi.org/10.1145/3658194</a>.'
  ieee: 'C. Hafner, M. Ly, and C. Wojtan, “Spin-it faster: Quadrics solve all topology
    optimization problems that depend only on mass moments,” <i>Transactions on Graphics</i>,
    vol. 43, no. 4. Association for Computing Machinery, 2024.'
  ista: 'Hafner C, Ly M, Wojtan C. 2024. Spin-it faster: Quadrics solve all topology
    optimization problems that depend only on mass moments. Transactions on Graphics.
    43(4), 78.'
  mla: 'Hafner, Christian, et al. “Spin-It Faster: Quadrics Solve All Topology Optimization
    Problems That Depend Only on Mass Moments.” <i>Transactions on Graphics</i>, vol.
    43, no. 4, 78, Association for Computing Machinery, 2024, doi:<a href="https://doi.org/10.1145/3658194">10.1145/3658194</a>.'
  short: C. Hafner, M. Ly, C. Wojtan, Transactions on Graphics 43 (2024).
conference:
  end_date: 2024-08-01
  location: Denver, Colorado
  start_date: 2024-07-28
corr_author: '1'
date_created: 2024-07-05T12:08:57Z
date_published: 2024-07-01T00:00:00Z
date_updated: 2025-09-08T08:29:09Z
day: '01'
ddc:
- '516'
department:
- _id: ChWo
doi: 10.1145/3658194
external_id:
  isi:
  - '001289270900045'
file:
- access_level: open_access
  checksum: 0dc9f5a6422b8a49a79026900f349ee5
  content_type: application/pdf
  creator: chafner
  date_created: 2024-07-05T12:05:17Z
  date_updated: 2024-07-05T12:05:17Z
  file_id: '17204'
  file_name: sif-final.pdf
  file_size: 7225150
  relation: main_file
  success: 1
- access_level: open_access
  checksum: cde433c6a40688d5f1187fb5721f6f94
  content_type: application/pdf
  creator: chafner
  date_created: 2024-07-05T12:06:03Z
  date_updated: 2024-07-05T12:06:03Z
  file_id: '17205'
  file_name: sif-supp-final.pdf
  file_size: 397262
  relation: supplementary_material
- access_level: open_access
  checksum: c0457a09c2ab9a1c2935c995dcc84907
  content_type: video/mp4
  creator: chafner
  date_created: 2024-07-17T09:29:13Z
  date_updated: 2024-07-17T09:29:13Z
  file_id: '17276'
  file_name: sif-video-final.mp4
  file_size: 170001305
  relation: supplementary_material
  title: Submission Video
file_date_updated: 2024-07-17T09:29:13Z
has_accepted_license: '1'
intvolume: '        43'
isi: 1
issue: '4'
keyword:
- Topology Optimization
- Mass Moments
- Computational Geometry
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
project:
- _id: 34bc2376-11ca-11ed-8bc3-9a3b3961a088
  grant_number: '101045083'
  name: Computational Discovery of Numerical Algorithms for Animation and Simulation
    of Natural Phenomena
publication: Transactions on Graphics
publication_identifier:
  eissn:
  - 1557-7368
  issn:
  - 0730-0301
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Spin-it faster: Quadrics solve all topology optimization problems that depend
  only on mass moments'
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 43
year: '2024'
...
---
_id: '12897'
abstract:
- lang: eng
  text: "Inverse design problems in fabrication-aware shape optimization are typically
    solved on discrete representations such as polygonal meshes. This thesis argues
    that there are benefits to treating these problems in the same domain as human
    designers, namely, the parametric one. One reason is that discretizing a parametric
    model usually removes the capability of making further manual changes to the design,
    because the human intent is captured by the shape parameters. Beyond this, knowledge
    about a design problem can sometimes reveal a structure that is present in a smooth
    representation, but is fundamentally altered by discretizing. In this case, working
    in the parametric domain may even simplify the optimization task. We present two
    lines of research that explore both of these aspects of fabrication-aware shape
    optimization on parametric representations.\r\n\r\nThe first project studies the
    design of plane elastic curves and Kirchhoff rods, which are common mathematical
    models for describing the deformation of thin elastic rods such as beams, ribbons,
    cables, and hair. Our main contribution is a characterization of all curved shapes
    that can be attained by bending and twisting elastic rods having a stiffness that
    is allowed to vary across the length. Elements like these can be manufactured
    using digital fabrication devices such as 3d printers and digital cutters, and
    have applications in free-form architecture and soft robotics.\r\n\r\nWe show
    that the family of curved shapes that can be produced this way admits geometric
    description that is concise and computationally convenient. In the case of plane
    curves, the geometric description is intuitive enough to allow a designer to determine
    whether a curved shape is physically achievable by visual inspection alone. We
    also present shape optimization algorithms that convert a user-defined curve in
    the plane or in three dimensions into the geometry of an elastic rod that will
    naturally deform to follow this curve when its endpoints are attached to a support
    structure. Implemented in an interactive software design tool, the rod geometry
    is generated in real time as the user edits a curve and enables fast prototyping.
    \r\n\r\nThe second project tackles the problem of general-purpose shape optimization
    on CAD models using a novel variant of the extended finite element method (XFEM).
    Our goal is the decoupling between the simulation mesh and the CAD model, so no
    geometry-dependent meshing or remeshing needs to be performed when the CAD parameters
    change during optimization. This is achieved by discretizing the embedding space
    of the CAD model, and using a new high-accuracy numerical integration method to
    enable XFEM on free-form elements bounded by the parametric surface patches of
    the model. Our simulation is differentiable from the CAD parameters to the simulation
    output, which enables us to use off-the-shelf gradient-based optimization procedures.
    The result is a method that fits seamlessly into the CAD workflow because it works
    on the same representation as the designer, enabling the alternation of manual
    editing and fabrication-aware optimization at will."
acknowledged_ssus:
- _id: M-Shop
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
citation:
  ama: 'Hafner C. Inverse shape design with parametric representations: Kirchhoff
    Rods and parametric surface models. 2023. doi:<a href="https://doi.org/10.15479/at:ista:12897">10.15479/at:ista:12897</a>'
  apa: 'Hafner, C. (2023). <i>Inverse shape design with parametric representations:
    Kirchhoff Rods and parametric surface models</i>. Institute of Science and Technology
    Austria. <a href="https://doi.org/10.15479/at:ista:12897">https://doi.org/10.15479/at:ista:12897</a>'
  chicago: 'Hafner, Christian. “Inverse Shape Design with Parametric Representations:
    Kirchhoff Rods and Parametric Surface Models.” Institute of Science and Technology
    Austria, 2023. <a href="https://doi.org/10.15479/at:ista:12897">https://doi.org/10.15479/at:ista:12897</a>.'
  ieee: 'C. Hafner, “Inverse shape design with parametric representations: Kirchhoff
    Rods and parametric surface models,” Institute of Science and Technology Austria,
    2023.'
  ista: 'Hafner C. 2023. Inverse shape design with parametric representations: Kirchhoff
    Rods and parametric surface models. Institute of Science and Technology Austria.'
  mla: 'Hafner, Christian. <i>Inverse Shape Design with Parametric Representations:
    Kirchhoff Rods and Parametric Surface Models</i>. Institute of Science and Technology
    Austria, 2023, doi:<a href="https://doi.org/10.15479/at:ista:12897">10.15479/at:ista:12897</a>.'
  short: 'C. Hafner, Inverse Shape Design with Parametric Representations: Kirchhoff
    Rods and Parametric Surface Models, Institute of Science and Technology Austria,
    2023.'
corr_author: '1'
date_created: 2023-05-05T10:40:14Z
date_published: 2023-05-05T00:00:00Z
date_updated: 2025-04-15T07:16:15Z
day: '05'
ddc:
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- '004'
- '518'
- '531'
degree_awarded: PhD
department:
- _id: GradSch
- _id: BeBi
doi: 10.15479/at:ista:12897
ec_funded: 1
file:
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file_date_updated: 2023-12-08T23:30:04Z
has_accepted_license: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '180'
project:
- _id: 24F9549A-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '715767'
  name: 'MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and
    Modeling'
publication_identifier:
  isbn:
  - 978-3-99078-031-2
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
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  - id: '13188'
    relation: dissertation_contains
    status: public
  - id: '7117'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Bernd
  full_name: Bickel, Bernd
  id: 49876194-F248-11E8-B48F-1D18A9856A87
  last_name: Bickel
  orcid: 0000-0001-6511-9385
title: 'Inverse shape design with parametric representations: Kirchhoff Rods and parametric
  surface models'
type: dissertation
user_id: 400429CC-F248-11E8-B48F-1D18A9856A87
year: '2023'
...
---
_id: '12972'
abstract:
- lang: eng
  text: Embroidery is a long-standing and high-quality approach to making logos and
    images on textiles. Nowadays, it can also be performed via automated machines
    that weave threads with high spatial accuracy. A characteristic feature of the
    appearance of the threads is a high degree of anisotropy. The anisotropic behavior
    is caused by depositing thin but long strings of thread. As a result, the stitched
    patterns convey both color and direction. Artists leverage this anisotropic behavior
    to enhance pure color images with textures, illusions of motion, or depth cues.
    However, designing colorful embroidery patterns with prescribed directionality
    is a challenging task, one usually requiring an expert designer. In this work,
    we propose an interactive algorithm that generates machine-fabricable embroidery
    patterns from multi-chromatic images equipped with user-specified directionality
    fields.We cast the problem of finding a stitching pattern into vector theory.
    To find a suitable stitching pattern, we extract sources and sinks from the divergence
    field of the vector field extracted from the input and use them to trace streamlines.
    We further optimize the streamlines to guarantee a smooth and connected stitching
    pattern. The generated patterns approximate the color distribution constrained
    by the directionality field. To allow for further artistic control, the trade-off
    between color match and directionality match can be interactively explored via
    an intuitive slider. We showcase our approach by fabricating several embroidery
    paths.
acknowledgement: This work was supported by the European Research Council (ERC) under
  the European Union’s Horizon 2020 research and innovation program (grant agreement
  No 715767 – MATERIALIZABLE), and FWF Lise Meitner (Grant M 3319). We thank the anonymous
  reviewers for their insightful feedback; Solal Pirelli, Shardul Chiplunkar, and
  Paola Mejia for proofreading; everyone in the visual computing group at ISTA for
  inspiring lunch and coffee breaks; Thibault Tricard for help producing the results
  of Phasor Noise.
article_processing_charge: No
article_type: original
author:
- first_name: Zhenyuan
  full_name: Liu, Zhenyuan
  id: 70f0d7cf-ae65-11ec-a14f-89dfc5505b19
  last_name: Liu
  orcid: 0000-0001-9200-5690
- first_name: Michael
  full_name: Piovarci, Michael
  id: 62E473F4-5C99-11EA-A40E-AF823DDC885E
  last_name: Piovarci
  orcid: 0000-0002-5062-4474
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Raphael
  full_name: Charrondiere, Raphael
  id: a3a24133-2cc7-11ec-be88-8ddaf6f464b1
  last_name: Charrondiere
- first_name: Bernd
  full_name: Bickel, Bernd
  id: 49876194-F248-11E8-B48F-1D18A9856A87
  last_name: Bickel
  orcid: 0000-0001-6511-9385
citation:
  ama: Liu Z, Piovarci M, Hafner C, Charrondiere R, Bickel B. Directionality-aware
    design of embroidery patterns. <i>Computer Graphics Forum</i>. 2023;42(2):397-409.
    doi:<a href="https://doi.org/10.1111/cgf.14770 ">10.1111/cgf.14770 </a>
  apa: 'Liu, Z., Piovarci, M., Hafner, C., Charrondiere, R., &#38; Bickel, B. (2023).
    Directionality-aware design of embroidery patterns. <i>Computer Graphics Forum</i>.
    Saarbrucken, Germany: Wiley. <a href="https://doi.org/10.1111/cgf.14770 ">https://doi.org/10.1111/cgf.14770
    </a>'
  chicago: Liu, Zhenyuan, Michael Piovarci, Christian Hafner, Raphael Charrondiere,
    and Bernd Bickel. “Directionality-Aware Design of Embroidery Patterns.” <i>Computer
    Graphics Forum</i>. Wiley, 2023. <a href="https://doi.org/10.1111/cgf.14770 ">https://doi.org/10.1111/cgf.14770
    </a>.
  ieee: Z. Liu, M. Piovarci, C. Hafner, R. Charrondiere, and B. Bickel, “Directionality-aware
    design of embroidery patterns,” <i>Computer Graphics Forum</i>, vol. 42, no. 2.
    Wiley, pp. 397–409, 2023.
  ista: Liu Z, Piovarci M, Hafner C, Charrondiere R, Bickel B. 2023. Directionality-aware
    design of embroidery patterns. Computer Graphics Forum. 42(2), 397–409.
  mla: Liu, Zhenyuan, et al. “Directionality-Aware Design of Embroidery Patterns.”
    <i>Computer Graphics Forum</i>, vol. 42, no. 2, Wiley, 2023, pp. 397–409, doi:<a
    href="https://doi.org/10.1111/cgf.14770 ">10.1111/cgf.14770 </a>.
  short: Z. Liu, M. Piovarci, C. Hafner, R. Charrondiere, B. Bickel, Computer Graphics
    Forum 42 (2023) 397–409.
conference:
  end_date: 2023-05-12
  location: Saarbrucken, Germany
  name: 'EG: Eurographics'
  start_date: 2023-05-08
corr_author: '1'
date_created: 2023-05-16T08:47:25Z
date_published: 2023-05-08T00:00:00Z
date_updated: 2025-04-14T07:28:57Z
day: '08'
ddc:
- '004'
department:
- _id: BeBi
doi: '10.1111/cgf.14770 '
ec_funded: 1
external_id:
  isi:
  - '001000062600033'
file:
- access_level: open_access
  checksum: 4c188c2be4745467a8790bbf5d6491aa
  content_type: application/pdf
  creator: mpiovarc
  date_created: 2023-05-16T08:28:37Z
  date_updated: 2023-05-16T08:28:37Z
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  file_size: 24003702
  relation: main_file
  success: 1
file_date_updated: 2023-05-16T08:28:37Z
has_accepted_license: '1'
intvolume: '        42'
isi: 1
issue: '2'
keyword:
- embroidery
- design
- directionality
- density
- image
language:
- iso: eng
license: https://creativecommons.org/licenses/by-nc-nd/4.0/
month: '05'
oa: 1
oa_version: Published Version
page: 397-409
project:
- _id: eb901961-77a9-11ec-83b8-f5c883a62027
  grant_number: M03319
  name: Perception-Aware Appearance Fabrication
- _id: 24F9549A-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '715767'
  name: 'MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and
    Modeling'
publication: Computer Graphics Forum
publication_identifier:
  issn:
  - 1467-8659
publication_status: published
publisher: Wiley
quality_controlled: '1'
scopus_import: '1'
status: public
title: Directionality-aware design of embroidery patterns
tmp:
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  name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
    (CC BY-NC-ND 4.0)
  short: CC BY-NC-ND (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 42
year: '2023'
...
---
_id: '13188'
abstract:
- lang: eng
  text: "The Kirchhoff rod model describes the bending and twisting of slender elastic
    rods in three dimensions, and has been widely studied to enable the prediction
    of how a rod will deform, given its geometry and boundary conditions. In this
    work, we study a number of inverse problems with the goal of computing the geometry
    of a straight rod that will automatically deform to match a curved target shape
    after attaching its endpoints to a support structure. Our solution lets us finely
    control the static equilibrium state of a rod by varying the cross-sectional profiles
    along its length.\r\nWe also show that the set of physically realizable equilibrium
    states admits a concise geometric description in terms of linear line complexes,
    which leads to very efficient computational design algorithms. Implemented in
    an interactive software tool, they allow us to convert three-dimensional hand-drawn
    spline curves to elastic rods, and give feedback about the feasibility and practicality
    of a design in real time. We demonstrate the efficacy of our method by designing
    and manufacturing several physical prototypes with applications to interior design
    and soft robotics."
acknowledged_ssus:
- _id: M-Shop
acknowledgement: We thank the anonymous reviewers for their generous feedback, and
  Julian Fischer for his help in proving Proposition 1. This project has received
  funding from the European Research Council (ERC) under the European Union’s Horizon
  2020 research and innovation programme (grant agreement No. 715767).
article_number: '171'
article_processing_charge: No
article_type: original
author:
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Bernd
  full_name: Bickel, Bernd
  id: 49876194-F248-11E8-B48F-1D18A9856A87
  last_name: Bickel
  orcid: 0000-0001-6511-9385
citation:
  ama: Hafner C, Bickel B. The design space of Kirchhoff rods. <i>ACM Transactions
    on Graphics</i>. 2023;42(5). doi:<a href="https://doi.org/10.1145/3606033">10.1145/3606033</a>
  apa: Hafner, C., &#38; Bickel, B. (2023). The design space of Kirchhoff rods. <i>ACM
    Transactions on Graphics</i>. Association for Computing Machinery. <a href="https://doi.org/10.1145/3606033">https://doi.org/10.1145/3606033</a>
  chicago: Hafner, Christian, and Bernd Bickel. “The Design Space of Kirchhoff Rods.”
    <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2023.
    <a href="https://doi.org/10.1145/3606033">https://doi.org/10.1145/3606033</a>.
  ieee: C. Hafner and B. Bickel, “The design space of Kirchhoff rods,” <i>ACM Transactions
    on Graphics</i>, vol. 42, no. 5. Association for Computing Machinery, 2023.
  ista: Hafner C, Bickel B. 2023. The design space of Kirchhoff rods. ACM Transactions
    on Graphics. 42(5), 171.
  mla: Hafner, Christian, and Bernd Bickel. “The Design Space of Kirchhoff Rods.”
    <i>ACM Transactions on Graphics</i>, vol. 42, no. 5, 171, Association for Computing
    Machinery, 2023, doi:<a href="https://doi.org/10.1145/3606033">10.1145/3606033</a>.
  short: C. Hafner, B. Bickel, ACM Transactions on Graphics 42 (2023).
corr_author: '1'
date_created: 2023-07-04T07:41:30Z
date_published: 2023-09-20T00:00:00Z
date_updated: 2026-06-23T22:31:11Z
day: '20'
ddc:
- '516'
department:
- _id: BeBi
doi: 10.1145/3606033
ec_funded: 1
external_id:
  isi:
  - '001086833300010'
file:
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  content_type: application/pdf
  creator: chafner
  date_created: 2023-07-04T08:11:28Z
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  creator: chafner
  date_created: 2023-07-04T07:46:28Z
  date_updated: 2023-07-04T07:46:28Z
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  file_name: supp-main.pdf
  file_size: 420909
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  title: Supplemental Material with Proofs
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  checksum: 4ab647e4f03c711e1e6a5fc1eb8684db
  content_type: application/pdf
  creator: chafner
  date_created: 2023-07-04T07:46:30Z
  date_updated: 2023-07-04T07:46:30Z
  file_id: '13191'
  file_name: supp-cheat.pdf
  file_size: 430086
  relation: supplementary_material
  title: Cheat Sheet for Notation
- access_level: open_access
  checksum: c0fd9a57d012046de90c185ffa904b76
  content_type: video/mp4
  creator: chafner
  date_created: 2023-07-04T07:46:39Z
  date_updated: 2023-07-04T07:46:39Z
  file_id: '13192'
  file_name: kirchhoff-video-final.mp4
  file_size: 268088064
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  title: Supplemental Video
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  checksum: 71b00712b489ada2cd9815910ee180a9
  content_type: application/x-zip-compressed
  creator: chafner
  date_created: 2023-07-04T07:47:10Z
  date_updated: 2023-07-04T07:47:10Z
  file_id: '13193'
  file_name: matlab-submission.zip
  file_size: 25790
  relation: supplementary_material
  title: Matlab Source Code with Example
file_date_updated: 2023-07-04T08:11:28Z
has_accepted_license: '1'
intvolume: '        42'
isi: 1
issue: '5'
keyword:
- Computer Graphics
- Computational Design
- Computational Geometry
- Shape Modeling
language:
- iso: eng
month: '09'
oa: 1
oa_version: Submitted Version
project:
- _id: 24F9549A-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '715767'
  name: 'MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and
    Modeling'
publication: ACM Transactions on Graphics
publication_identifier:
  eissn:
  - 1557-7368
  issn:
  - 0730-0301
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
related_material:
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  - id: '12897'
    relation: part_of_dissertation
    status: public
scopus_import: '1'
status: public
title: The design space of Kirchhoff rods
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 42
year: '2023'
...
---
_id: '9817'
abstract:
- lang: eng
  text: Elastic bending of initially flat slender elements allows the realization
    and economic fabrication of intriguing curved shapes. In this work, we derive
    an intuitive but rigorous geometric characterization of the design space of plane
    elastic rods with variable stiffness. It enables designers to determine which
    shapes are physically viable with active bending by visual inspection alone. Building
    on these insights, we propose a method for efficiently designing the geometry
    of a flat elastic rod that realizes a target equilibrium curve, which only requires
    solving a linear program. We implement this method in an interactive computational
    design tool that gives feedback about the feasibility of a design, and computes
    the geometry of the structural elements necessary to realize it within an instant.
    The tool also offers an iterative optimization routine that improves the fabricability
    of a model while modifying it as little as possible. In addition, we use our geometric
    characterization to derive an algorithm for analyzing and recovering the stability
    of elastic curves that would otherwise snap out of their unstable equilibrium
    shapes by buckling. We show the efficacy of our approach by designing and manufacturing
    several physical models that are assembled from flat elements.
acknowledgement: "We thank the anonymous reviewers for their generous feedback, and
  Michal Piovarči for his help in producing the supplemental video. This project has
  received funding from the European Research Council (ERC) under the European Union’s
  Horizon 2020 research and innovation programme (grant agreement No 715767).\r\n"
article_number: '126'
article_processing_charge: No
article_type: original
author:
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Bernd
  full_name: Bickel, Bernd
  id: 49876194-F248-11E8-B48F-1D18A9856A87
  last_name: Bickel
  orcid: 0000-0001-6511-9385
citation:
  ama: Hafner C, Bickel B. The design space of plane elastic curves. <i>ACM Transactions
    on Graphics</i>. 2021;40(4). doi:<a href="https://doi.org/10.1145/3450626.3459800">10.1145/3450626.3459800</a>
  apa: 'Hafner, C., &#38; Bickel, B. (2021). The design space of plane elastic curves.
    <i>ACM Transactions on Graphics</i>. Virtual: Association for Computing Machinery.
    <a href="https://doi.org/10.1145/3450626.3459800">https://doi.org/10.1145/3450626.3459800</a>'
  chicago: Hafner, Christian, and Bernd Bickel. “The Design Space of Plane Elastic
    Curves.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery,
    2021. <a href="https://doi.org/10.1145/3450626.3459800">https://doi.org/10.1145/3450626.3459800</a>.
  ieee: C. Hafner and B. Bickel, “The design space of plane elastic curves,” <i>ACM
    Transactions on Graphics</i>, vol. 40, no. 4. Association for Computing Machinery,
    2021.
  ista: Hafner C, Bickel B. 2021. The design space of plane elastic curves. ACM Transactions
    on Graphics. 40(4), 126.
  mla: Hafner, Christian, and Bernd Bickel. “The Design Space of Plane Elastic Curves.”
    <i>ACM Transactions on Graphics</i>, vol. 40, no. 4, 126, Association for Computing
    Machinery, 2021, doi:<a href="https://doi.org/10.1145/3450626.3459800">10.1145/3450626.3459800</a>.
  short: C. Hafner, B. Bickel, ACM Transactions on Graphics 40 (2021).
conference:
  end_date: 2021-08-13
  location: Virtual
  name: 'SIGGRAF: Special Interest Group on Computer Graphics and Interactive Techniques'
  start_date: 2021-08-09
date_created: 2021-08-08T22:01:26Z
date_published: 2021-07-19T00:00:00Z
date_updated: 2026-06-23T22:31:11Z
day: '19'
ddc:
- '516'
department:
- _id: BeBi
doi: 10.1145/3450626.3459800
ec_funded: 1
external_id:
  isi:
  - '000674930900091'
file:
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  checksum: 7e5d08ce46b0451b3102eacd3d00f85f
  content_type: application/pdf
  creator: chafner
  date_created: 2021-10-18T10:42:15Z
  date_updated: 2021-10-18T10:42:15Z
  file_id: '10150'
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  date_created: 2021-10-18T10:42:22Z
  date_updated: 2021-10-18T10:42:22Z
  file_id: '10151'
  file_name: elastic-curves-supp.pdf
  file_size: 547156
  relation: supplementary_material
file_date_updated: 2021-10-18T10:42:22Z
has_accepted_license: '1'
intvolume: '        40'
isi: 1
issue: '4'
keyword:
- Computing methodologies
- shape modeling
- modeling and simulation
- theory of computation
- computational geometry
- mathematics of computing
- mathematical optimization
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
project:
- _id: 24F9549A-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '715767'
  name: 'MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and
    Modeling'
publication: ACM Transactions on Graphics
publication_identifier:
  eissn:
  - 1557-7368
  issn:
  - 0730-0301
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
related_material:
  link:
  - description: News on IST Website
    relation: press_release
    url: https://ist.ac.at/en/news/designing-with-elastic-structures/
  record:
  - id: '12897'
    relation: dissertation_contains
    status: public
scopus_import: '1'
status: public
title: The design space of plane elastic curves
tmp:
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  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 40
year: '2021'
...
---
_id: '8766'
abstract:
- lang: eng
  text: "The “procedural” approach to animating ocean waves is the dominant algorithm
    for animating larger bodies of water in\r\ninteractive applications as well as
    in off-line productions — it provides high visual quality with a low computational
    demand. In this paper, we widen the applicability of procedural water wave animation
    with an extension that guarantees the satisfaction of boundary conditions imposed
    by terrain while still approximating physical wave behavior. In combination with
    a particle system that models wave breaking, foam, and spray, this allows us to
    naturally model waves interacting with beaches and rocks. Our system is able to
    animate waves at large scales at interactive frame rates on a commodity PC."
article_processing_charge: No
article_type: original
author:
- first_name: Stefan
  full_name: Jeschke, Stefan
  id: 44D6411A-F248-11E8-B48F-1D18A9856A87
  last_name: Jeschke
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Nuttapong
  full_name: Chentanez, Nuttapong
  last_name: Chentanez
- first_name: Miles
  full_name: Macklin, Miles
  last_name: Macklin
- first_name: Matthias
  full_name: Müller-Fischer, Matthias
  last_name: Müller-Fischer
- first_name: Christopher J
  full_name: Wojtan, Christopher J
  id: 3C61F1D2-F248-11E8-B48F-1D18A9856A87
  last_name: Wojtan
  orcid: 0000-0001-6646-5546
citation:
  ama: Jeschke S, Hafner C, Chentanez N, Macklin M, Müller-Fischer M, Wojtan C. Making
    procedural water waves boundary-aware. <i>Computer Graphics forum</i>. 2020;39(8):47-54.
    doi:<a href="https://doi.org/10.1111/cgf.14100">10.1111/cgf.14100</a>
  apa: 'Jeschke, S., Hafner, C., Chentanez, N., Macklin, M., Müller-Fischer, M., &#38;
    Wojtan, C. (2020). Making procedural water waves boundary-aware. <i>Computer Graphics
    Forum</i>. Online Symposium: Wiley. <a href="https://doi.org/10.1111/cgf.14100">https://doi.org/10.1111/cgf.14100</a>'
  chicago: Jeschke, Stefan, Christian Hafner, Nuttapong Chentanez, Miles Macklin,
    Matthias Müller-Fischer, and Chris Wojtan. “Making Procedural Water Waves Boundary-Aware.”
    <i>Computer Graphics Forum</i>. Wiley, 2020. <a href="https://doi.org/10.1111/cgf.14100">https://doi.org/10.1111/cgf.14100</a>.
  ieee: S. Jeschke, C. Hafner, N. Chentanez, M. Macklin, M. Müller-Fischer, and C.
    Wojtan, “Making procedural water waves boundary-aware,” <i>Computer Graphics forum</i>,
    vol. 39, no. 8. Wiley, pp. 47–54, 2020.
  ista: Jeschke S, Hafner C, Chentanez N, Macklin M, Müller-Fischer M, Wojtan C. 2020.
    Making procedural water waves boundary-aware. Computer Graphics forum. 39(8),
    47–54.
  mla: Jeschke, Stefan, et al. “Making Procedural Water Waves Boundary-Aware.” <i>Computer
    Graphics Forum</i>, vol. 39, no. 8, Wiley, 2020, pp. 47–54, doi:<a href="https://doi.org/10.1111/cgf.14100">10.1111/cgf.14100</a>.
  short: S. Jeschke, C. Hafner, N. Chentanez, M. Macklin, M. Müller-Fischer, C. Wojtan,
    Computer Graphics Forum 39 (2020) 47–54.
conference:
  end_date: 2020-10-09
  location: Online Symposium
  name: 'SCA: Symposium on Computer Animation'
  start_date: 2020-10-06
date_created: 2020-11-17T10:47:48Z
date_published: 2020-12-01T00:00:00Z
date_updated: 2024-10-22T09:58:15Z
day: '01'
department:
- _id: ChWo
- _id: BeBi
doi: 10.1111/cgf.14100
ec_funded: 1
external_id:
  isi:
  - '000591780400005'
intvolume: '        39'
isi: 1
issue: '8'
language:
- iso: eng
month: '12'
oa_version: None
page: 47-54
project:
- _id: 2533E772-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '638176'
  name: 'Big Splash: Efficient Simulation of Natural Phenomena at Extremely Large
    Scales'
- _id: 24F9549A-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '715767'
  name: 'MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and
    Modeling'
publication: Computer Graphics forum
publication_status: published
publisher: Wiley
quality_controlled: '1'
scopus_import: '1'
status: public
title: Making procedural water waves boundary-aware
type: journal_article
user_id: 2EBD1598-F248-11E8-B48F-1D18A9856A87
volume: 39
year: '2020'
...
---
_id: '6442'
abstract:
- lang: eng
  text: This paper investigates the use of fundamental solutions for animating detailed
    linear water surface waves. We first propose an analytical solution for efficiently
    animating circular ripples in closed form. We then show how to adapt the method
    of fundamental solutions (MFS) to create ambient waves interacting with complex
    obstacles. Subsequently, we present a novel wavelet-based discretization which
    outperforms the state of the art MFS approach for simulating time-varying water
    surface waves with moving obstacles. Our results feature high-resolution spatial
    details, interactions with complex boundaries, and large open ocean domains. Our
    method compares favorably with previous work as well as known analytical solutions.
    We also present comparisons between our method and real world examples.
acknowledged_ssus:
- _id: ScienComp
article_number: '130'
article_processing_charge: No
author:
- first_name: Camille
  full_name: Schreck, Camille
  id: 2B14B676-F248-11E8-B48F-1D18A9856A87
  last_name: Schreck
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Christopher J
  full_name: Wojtan, Christopher J
  id: 3C61F1D2-F248-11E8-B48F-1D18A9856A87
  last_name: Wojtan
  orcid: 0000-0001-6646-5546
citation:
  ama: Schreck C, Hafner C, Wojtan C. Fundamental solutions for water wave animation.
    <i>ACM Transactions on Graphics</i>. 2019;38(4). doi:<a href="https://doi.org/10.1145/3306346.3323002">10.1145/3306346.3323002</a>
  apa: Schreck, C., Hafner, C., &#38; Wojtan, C. (2019). Fundamental solutions for
    water wave animation. <i>ACM Transactions on Graphics</i>. ACM. <a href="https://doi.org/10.1145/3306346.3323002">https://doi.org/10.1145/3306346.3323002</a>
  chicago: Schreck, Camille, Christian Hafner, and Chris Wojtan. “Fundamental Solutions
    for Water Wave Animation.” <i>ACM Transactions on Graphics</i>. ACM, 2019. <a
    href="https://doi.org/10.1145/3306346.3323002">https://doi.org/10.1145/3306346.3323002</a>.
  ieee: C. Schreck, C. Hafner, and C. Wojtan, “Fundamental solutions for water wave
    animation,” <i>ACM Transactions on Graphics</i>, vol. 38, no. 4. ACM, 2019.
  ista: Schreck C, Hafner C, Wojtan C. 2019. Fundamental solutions for water wave
    animation. ACM Transactions on Graphics. 38(4), 130.
  mla: Schreck, Camille, et al. “Fundamental Solutions for Water Wave Animation.”
    <i>ACM Transactions on Graphics</i>, vol. 38, no. 4, 130, ACM, 2019, doi:<a href="https://doi.org/10.1145/3306346.3323002">10.1145/3306346.3323002</a>.
  short: C. Schreck, C. Hafner, C. Wojtan, ACM Transactions on Graphics 38 (2019).
date_created: 2019-05-14T07:04:06Z
date_published: 2019-07-01T00:00:00Z
date_updated: 2024-10-22T09:58:22Z
day: '01'
ddc:
- '000'
- '005'
department:
- _id: ChWo
doi: 10.1145/3306346.3323002
ec_funded: 1
external_id:
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  - '000475740600104'
file:
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  date_updated: 2020-07-14T12:47:30Z
  file_id: '6443'
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  file_size: 44328918
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file_date_updated: 2020-07-14T12:47:30Z
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intvolume: '        38'
isi: 1
issue: '4'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Submitted Version
project:
- _id: 2533E772-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '638176'
  name: 'Big Splash: Efficient Simulation of Natural Phenomena at Extremely Large
    Scales'
- _id: 24F9549A-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '715767'
  name: 'MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and
    Modeling'
- _id: 2564DBCA-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '665385'
  name: International IST Doctoral Program
publication: ACM Transactions on Graphics
publication_status: published
publisher: ACM
quality_controlled: '1'
related_material:
  link:
  - description: News on IST Homepage
    relation: press_release
    url: https://ist.ac.at/en/news/new-method-makes-realistic-water-wave-animations-more-efficient/
scopus_import: '1'
status: public
title: Fundamental solutions for water wave animation
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 38
year: '2019'
...
---
_id: '7117'
abstract:
- lang: eng
  text: We propose a novel generic shape optimization method for CAD models based
    on the eXtended Finite Element Method (XFEM). Our method works directly on the
    intersection between the model and a regular simulation grid, without the need
    to mesh or remesh, thus removing a bottleneck of classical shape optimization
    strategies. This is made possible by a novel hierarchical integration scheme that
    accurately integrates finite element quantities with sub-element precision. For
    optimization, we efficiently compute analytical shape derivatives of the entire
    framework, from model intersection to integration rule generation and XFEM simulation.
    Moreover, we describe a differentiable projection of shape parameters onto a constraint
    manifold spanned by user-specified shape preservation, consistency, and manufacturability
    constraints. We demonstrate the utility of our approach by optimizing mass distribution,
    strength-to-weight ratio, and inverse elastic shape design objectives directly
    on parameterized 3D CAD models.
article_number: '157'
article_processing_charge: No
article_type: original
author:
- first_name: Christian
  full_name: Hafner, Christian
  id: 400429CC-F248-11E8-B48F-1D18A9856A87
  last_name: Hafner
- first_name: Christian
  full_name: Schumacher, Christian
  last_name: Schumacher
- first_name: Espen
  full_name: Knoop, Espen
  last_name: Knoop
- first_name: Thomas
  full_name: Auzinger, Thomas
  id: 4718F954-F248-11E8-B48F-1D18A9856A87
  last_name: Auzinger
  orcid: 0000-0002-1546-3265
- first_name: Bernd
  full_name: Bickel, Bernd
  id: 49876194-F248-11E8-B48F-1D18A9856A87
  last_name: Bickel
  orcid: 0000-0001-6511-9385
- first_name: Moritz
  full_name: Bächer, Moritz
  last_name: Bächer
citation:
  ama: 'Hafner C, Schumacher C, Knoop E, Auzinger T, Bickel B, Bächer M. X-CAD: Optimizing
    CAD Models with Extended Finite Elements. <i>ACM Transactions on Graphics</i>.
    2019;38(6). doi:<a href="https://doi.org/10.1145/3355089.3356576">10.1145/3355089.3356576</a>'
  apa: 'Hafner, C., Schumacher, C., Knoop, E., Auzinger, T., Bickel, B., &#38; Bächer,
    M. (2019). X-CAD: Optimizing CAD Models with Extended Finite Elements. <i>ACM
    Transactions on Graphics</i>. ACM. <a href="https://doi.org/10.1145/3355089.3356576">https://doi.org/10.1145/3355089.3356576</a>'
  chicago: 'Hafner, Christian, Christian Schumacher, Espen Knoop, Thomas Auzinger,
    Bernd Bickel, and Moritz Bächer. “X-CAD: Optimizing CAD Models with Extended Finite
    Elements.” <i>ACM Transactions on Graphics</i>. ACM, 2019. <a href="https://doi.org/10.1145/3355089.3356576">https://doi.org/10.1145/3355089.3356576</a>.'
  ieee: 'C. Hafner, C. Schumacher, E. Knoop, T. Auzinger, B. Bickel, and M. Bächer,
    “X-CAD: Optimizing CAD Models with Extended Finite Elements,” <i>ACM Transactions
    on Graphics</i>, vol. 38, no. 6. ACM, 2019.'
  ista: 'Hafner C, Schumacher C, Knoop E, Auzinger T, Bickel B, Bächer M. 2019. X-CAD:
    Optimizing CAD Models with Extended Finite Elements. ACM Transactions on Graphics.
    38(6), 157.'
  mla: 'Hafner, Christian, et al. “X-CAD: Optimizing CAD Models with Extended Finite
    Elements.” <i>ACM Transactions on Graphics</i>, vol. 38, no. 6, 157, ACM, 2019,
    doi:<a href="https://doi.org/10.1145/3355089.3356576">10.1145/3355089.3356576</a>.'
  short: C. Hafner, C. Schumacher, E. Knoop, T. Auzinger, B. Bickel, M. Bächer, ACM
    Transactions on Graphics 38 (2019).
date_created: 2019-11-26T14:22:09Z
date_published: 2019-11-06T00:00:00Z
date_updated: 2026-06-23T22:31:11Z
day: '06'
ddc:
- '000'
department:
- _id: BeBi
doi: 10.1145/3355089.3356576
ec_funded: 1
external_id:
  isi:
  - '000498397300007'
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  checksum: 56a2fb019adcb556d2b022f5e5acb68c
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  creator: bbickel
  date_created: 2019-11-26T14:24:26Z
  date_updated: 2020-07-14T12:47:49Z
  file_id: '7119'
  file_name: xcad_sup_mat_siga19.pdf
  file_size: 1673176
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  creator: bbickel
  date_created: 2019-11-26T14:24:27Z
  date_updated: 2020-07-14T12:47:49Z
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month: '11'
oa: 1
oa_version: Submitted Version
project:
- _id: 24F9549A-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '715767'
  name: 'MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and
    Modeling'
publication: ACM Transactions on Graphics
publication_identifier:
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quality_controlled: '1'
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...
