Samara Ren

Samara Ren

Assistant Professor in Computer Science

ISTA

Biography

Yingying (Samara) Ren is an Assistant Professor in Computer Science at ISTA and leads the Geometric Computing and Digital Fabrication group. Her group focuses on research in digital fabrication, physics-based simulation, and computational inverse design. By leveraging geometric reasoning and numerical methods, her group aims to create new structures and materials with applications in medical devices, architecture, soft robotics, and more.

Samara completed her PhD at the School of Computer and Communication Sciences at EPFL, where she was advised by Professor Mark Pauly at EPFL and co-advised by Professor Julian Panetta at UC Davis. Previously she received her dual degrees from the University of Illinois at Urbana-Champaign in Mathematics (with highest distinction) and Computer Science (with highest honors).

Interests
  • Physics-based Simulation
  • Inverse Design Optimization
  • Digital Fabrication
  • Geometric Computing
Education

  • PhD in Computer Science, 2019 - 2024

    EPFL

  • BSc in Computer Science, BSc in Mathematics, 2015 - 2019

    UIUC

Publications

Tencers: Tension-Constrained Elastic Rods
We study ensembles of elastic rods that are tensioned by a small set of inextensible cables. The cables induce forces that deform the initially straight, but flexible rods into 3D space curves at equilibrium. Rods can be open or closed, knotted, and arranged in arbitrary topologies. We specifically focus on equilibrium states with no contacts among rods. Our setup can thus be seen as a generalization of classical tensegrities that are composed of rigid rods and tensile cables, to also support …
Liliane-Joy Dandy, Michele Vidulis, Yingying Ren, Mark Pauly
November, 2024 ACM Transactions on Graphics (TOG)
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Tencers: Tension-Constrained Elastic Rods
Computational Homogenization for Inverse Design of Surface-based Inflatables
Surface-based inflatables are composed of two thin layers of nearly inextensible sheet material joined together along carefully selected fusing curves. During inflation, pressure forces separate the two sheets to maximize the enclosed volume. The fusing curves restrict this expansion, leading to a spatially varying in-plane contraction and hence metric frustration. The inflated structure settles into a 3D equilibrium that balances pressure forces with the internal elastic forces of the sheets. …
Yingying Ren, Julian Panetta, Seiichi Suzuki, Uday Kusupati, Florin Isvoranu, Mark Pauly
January, 2024 ACM Transactions on Graphics (TOG)
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Computational Homogenization for Inverse Design of Surface-based Inflatables
Reach For the Arcs: Reconstructing Surfaces from SDFs via Tangent Points
Silvia Sellán, Yingying Ren, Christopher Batty, Oded Stein
January, 2024 SIGGRAPH 2024 Conference Papers
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Reach For the Arcs: Reconstructing Surfaces from SDFs via Tangent Points
C-shells: Deployable Gridshells with Curved Beams
We introduce a computational pipeline for simulating and designing C-shells, a new class of planar-to-spatial deployable linkage structures. A C-shell is composed of curved flexible beams connected at rotational joints that can be assembled in a stress-free planar configuration. When actuated, the elastic beams deform and the assembly deploys towards the target 3D shape. We propose two alternative computational design approaches for C-shells: (i) Forward exploration simulates the deployed shape …
Quentin Becker, Seiichi Suzuki, Yingying Ren, Davide Pellis, Julian Panetta, Mark Pauly
November, 2023 ACM SIGGRAPH Asia
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C-shells: Deployable Gridshells with Curved Beams
BamX: Rethinking Deployability in Architecture through Weaving
Deployable gridshells are a class of planar-to-spatial structures that achievea 3D curved geometry by inducing bending on a flat grid of elastic beams. However, theslender nature of these beams often conflicts with the structure’s load-bearing capacity.To address this issue, multiple layers are typically stacked to enhance out-of-planestiffness and prevent stability issues. The primary challenge then lies in deploying suchmulti-layered systems globally, as it requires significant shaping forces …
Seiichi Suzuki, Alison Martin, Yingying Ren, Tzu-Ying Chen, Stefana Parascho, Mark Pauly
October, 2023 Advances in Architectural Geometry
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BamX: Rethinking Deployability in Architecture through Weaving
Computational Exploration of Multistable Elastic Knots
We present an algorithmic approach to discover, study, and design multistable elastic knots. Elastic knots are physical realizations of closed curves embedded in 3-space. When endowed with the material thickness and bending resistance of a physical wire, these knots settle into equilibrium states that balance the forces induced by elastic deformation and self-contacts of the wire. In general, elastic knots can have many distinct equilibrium states, i.e. they are multistable …
Michele Vidulis, Yingying Ren, Julian Panetta, Eitan Grinspun, Mark Pauly
August, 2023 ACM SIGGRAPH
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Computational Exploration of Multistable Elastic Knots
From Kirigami to Hydrogels: A Tutorial on Designing Conformally Transformable Surfaces
Elastic surfaces that morph between multiple geometrical configurations are of significant engineering value, with applications ranging from the deployment of space-based photovoltaic arrays, the erection of temporary shelters, and the realization of flexible display systems, to understanding the encapsulation and release of viral RNAs. In general, ensuring that a shape with a planar rest configuration can deploy into a target three-dimensional (3D) shape is a nontrivial problem. Moreover, it is …
Yue Wang, Yingying Ren, Tian Chen
April, 2023 Journal of Applied Mechanics
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From Kirigami to Hydrogels: A Tutorial on Designing Conformally Transformable Surfaces
Umbrella Meshes: Elastic Mechanisms for Freeform Shape Deployment
We present a computational inverse design framework for a new class of volumetric deployable structures that have compact rest states and deploy into bending-active 3D target surfaces. Umbrella meshes consist of elastic beams, rigid plates, and hinge joints that can be directly printed or assembled in a zero-energy fabrication state. During deployment, as the elastic beams of varying heights rotate from vertical to horizontal configurations, the entire structure transforms from a compact block …
Yingying Ren, Uday Kusupati, Julian Panetta, Florin Isvoranu, Davide Pellis, Tian Chen, Mark Pauly (*joint first authors)
July, 2022 ACM SIGGRAPH
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Umbrella Meshes: Elastic Mechanisms for Freeform Shape Deployment
A Visibility-Based Approach to Computing Non-Deterministic Bouncing Strategies
Inspired by motion patterns of some commercially available mobile robots, we investigate the power of robots that move forward in straight lines until colliding with an environment boundary, at which point they can rotate in place and move forward again; we visualize this as the robot ‘‘bouncing’’ off boundaries. We define bounce rules governing how the robot should reorient after reaching a boundary, such as reorienting relative to its heading prior to collision, or relative to the normal of …
Alexandra Q Nilles, Yingying Ren, Israel Becerra, Steven M LaValle
September, 2021 The International Journal of Robotics Research
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A Visibility-Based Approach to Computing Non-Deterministic Bouncing Strategies
3D Weaving with Curved Ribbons
Basket weaving is a traditional craft for creating curved surfaces as an interwoven array of thin, flexible, and initially straight ribbons. The three-dimensional shape of a woven structure emerges through a complex interplay of the elastic bending behavior of the ribbons and the contact forces at their crossings. Curvature can be injected by carefully placing topological singu-larities in the otherwise regular weaving pattern. However, shape control through topology is highly non-trivial and …
Yingying Ren, Julian Panetta, Tian Chen, Florin Isvoranu, Samuel Poincloux, Christopher Brandt, Alison Martin, Mark Pauly
July, 2021 ACM SIGGRAPH
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3D Weaving with Curved Ribbons
A Combinatorial Method for Connecting BHV Spaces Representing Different Numbers of Taxa
The phylogenetic tree space introduced by Billera, Holmes, and Vogtmann (BHV tree space) is a CAT(0) continuous space that represents trees with edge weights with an intrinsic geodesic distance measure. The geodesic distance measure unique to BHV tree space is well known to be computable in polynomial time, which makes it a potentially powerful tool for optimization problems in phylogenetics and phylogenomics. Specifically, there is significant interest in comparing and combining phylogenetic …
Yingying Ren, Sihan Zha, Jingwen Bi, José A. Sanchez, Cara Monical, Michelle Delcourt, Rosemary K. Guzman, Ruth Davidson
December, 2017 Arxiv
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A Combinatorial Method for Connecting BHV Spaces Representing Different Numbers of Taxa