Lennart Bastian

dblp:317/0327 · DBLP profile ↗
← Back
7ranked-venue papers
4as first author
7since 2021 · last 2025
0000-0001-8088-3920ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Graphics, computer vision, multimedia, augmented reality and games · 5 · 4 first-author · 5 since 2021Artificial intelligence and machine learning · 3 · 2 first-author · 3 since 2021Applied, interdisciplinary, general and emerging computing · 3 · 2 first-author · 3 since 2021

Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.

Artificial intelligence
3 papers
3D vision · 28% Representation and self-supervised learning · 22% Graph learning · 14%
Computer graphics and multimedia
1 paper
Geometric modeling and processing · 100%

Topics — the 12 heaviest of 13, each with the papers that count most for it

TopicWeightPapersLastEvidence papers
Computer vision › Face, body and person analysis › human pose estimation
3d pose estimation
0.912025
Forecasting Continuous Non-Conservative Dynamical Systems in So(3) · ICCV 2025
Robotics › Motion planning and robot control
dynamic modeling
0.912025
Forecasting Continuous Non-Conservative Dynamical Systems in So(3) · ICCV 2025
Machine learning › Graph learning
graph neural network
0.912025
Copresheaf Topological Neural Networks: A Generalized Deep Learning Framework · NeurIPS 2025
Machine learning › Representation and self-supervised learning › representation learning
multi-scale representation learning
0.912025
Copresheaf Topological Neural Networks: A Generalized Deep Learning Framework · NeurIPS 2025
Machine learning › Deep learning architectures and training › neural differential equations
neural controlled differential equations
0.912025
Forecasting Continuous Non-Conservative Dynamical Systems in So(3) · ICCV 2025
Machine learning › Representation and self-supervised learning › representation learning
structured representation learning
0.912025
Copresheaf Topological Neural Networks: A Generalized Deep Learning Framework · NeurIPS 2025
Computer vision › 3D vision
3d shape analysis
0.812024
Hybrid Functional Maps for Crease-Aware Non-Isometric Shape Matching · CVPR 2024
Computer vision › 3D vision › shape matching
functional maps
0.812024
Hybrid Functional Maps for Crease-Aware Non-Isometric Shape Matching · CVPR 2024
Computer vision › 3D vision
shape matching
0.812024
Hybrid Functional Maps for Crease-Aware Non-Isometric Shape Matching · CVPR 2024
Machine learning › Graph learning
graph representation learning
0.312025
Copresheaf Topological Neural Networks: A Generalized Deep Learning Framework · NeurIPS 2025
Computer vision › Video understanding and tracking
object tracking
0.312025
Forecasting Continuous Non-Conservative Dynamical Systems in So(3) · ICCV 2025
Geometric modeling and processing
shape deformation
0.212024
Hybrid Functional Maps for Crease-Aware Non-Isometric Shape Matching · CVPR 2024

Methods — techniques the papers use, named apart from their topics

laplace-beltrami operator · 1.5functional maps · 1.5elastic thin-shell hessian · 1.5savitzky-golay paths · 0.9neural controlled differential equations · 0.9message passing · 0.9copresheaf theory · 0.9algebraic topology · 0.9
YearPublicationVenuePosition
2025 Forecasting Continuous Non-Conservative Dynamical Systems in So(3)
abstract
Modeling the rotation of moving objects is a fundamental task in computer vision, yet $SO(3)$ extrapolation still presents numerous challenges: (1) unknown quantities such as the moment of inertia complicate dynamics, (2) the presence of external forces and torques can lead to non-conservative kinematics, and (3) estimating evolving state trajectories under sparse, noisy observations requires robustness. We propose modeling trajectories of noisy pose estimates on the manifold of 3D rotations in a physically and geometrically meaningful way by leveraging Neural Controlled Differential Equations guided with $SO(3)$ Savitzky-Golay paths. Existing extrapolation methods often rely on energy conservation or constant velocity assumptions, limiting their applicability in real-world scenarios involving non-conservative forces. In contrast, our approach is agnostic to energy and momentum conservation while being robust to input noise, making it applicable to complex, non-inertial systems. Our approach is easily integrated as a module in existing pipelines and generalizes well to trajectories with unknown physical parameters. By learning to approximate object dynamics from noisy states during training, our model attains robust extrapolation capabilities in simulation and various real-world settings. Code is available at https://github.com/bastianlb/forecasting-rotational-dynamics
Lennart Bastian, Mohammad Rashed, Nassir Navab, Tolga Birdal
ICCV1
2025 Copresheaf Topological Neural Networks: A Generalized Deep Learning Framework
abstract
We introduce copresheaf topological neural networks (CTNNs), a powerful unifying framework that encapsulates a wide spectrum of deep learning architectures, designed to operate on structured data, including images, point clouds, graphs, meshes, and topological manifolds. While deep learning has profoundly impacted domains ranging from digital assistants to autonomous systems, the principled design of neural architectures tailored to specific tasks and data types remains one of the field's most persistent open challenges. CTNNs address this gap by formulating model design in the language of copresheaves, a concept from algebraic topology that generalizes most practical deep learning models in use today. This abstract yet constructive formulation yields a rich design space from which theoretically sound and practically effective solutions can be derived to tackle core challenges in representation learning, such as long-range dependencies, oversmoothing, heterophily, and non-Euclidean domains. Our empirical results on structured data benchmarks demonstrate that CTNNs consistently outperform conventional baselines, particularly in tasks requiring hierarchical or localized sensitivity. These results establish CTNNs as a principled multi-scale foundation for the next generation of deep learning architectures.
Mustafa Hajij, Lennart Bastian, Sarah Osentoski, Hardik Kabaria, John L. Davenport, Sheik Dawood, Balaji Cherukuri, Joseph G. Kocheemoolayil, Nastaran Shahmansouri, Adrian Lew, Theodore Papamarkou, Tolga Birdal
NeurIPS2
2025 Beyond Complete Shapes: A Benchmark for Quantitative Evaluation of 3D Shape Surface Matching Algorithms
abstract
Abstract Finding correspondences between 3D deformable shapes is an important and long‐standing problem in geometry processing, computer vision, graphics, and beyond. While various shape matching datasets exist, they are mostly static or limited in size, restricting their adaptation to different problem settings, including both full and partial shape matching. In particular the existing partial shape matching datasets are small (fewer than 100 shapes) and thus unsuitable for data‐hungry machine learning approaches. Moreover, the type of partiality present in existing datasets is often artificial and far from realistic. To address these limitations, we introduce a generic and flexible framework for the procedural generation of challenging full and partial shape matching datasets. Our framework allows the propagation of custom annotations across shapes, making it useful for various applications. By utilising our framework and manually creating cross‐dataset correspondences between seven existing (complete geometry) shape matching datasets, we propose a new large benchmark BeCoS with a total of 2543 shapes. Based on this, we offer several challenging benchmark settings, covering both full and partial matching, for which we evaluate respective state‐of‐the‐art methods as baselines. Visualisations and code of our benchmark can be found at: https://nafieamrani.github.io/BeCoS/ .
Viktoria Ehm, Nafie El Amrani, Yizheng Xie, Lennart Bastian, Weikang Wang 0004, Lu Sang, Dongliang Cao, Tobias Weißberg, Zorah Lähner, Daniel Cremers, Florian Bernard 0001
Comput. Graph. Forum4
2025 Beyond role-based surgical domain modeling: Generalizable re-identification in the operating room
abstract
Surgical domain models seek to optimize the surgical workflow through the incorporation of each staff member's role. However, mounting evidence indicates that team familiarity and individuality impact surgical outcomes. We present a novel staff-centric modeling approach that characterizes individual team members through their distinctive movement patterns and physical characteristics, enabling long-term tracking and analysis of surgical personnel across multiple procedures. To address the challenge of inter-clinic variability, we develop a generalizable re-identification framework that encodes sequences of 3D point clouds to capture shape and articulated motion patterns unique to each individual. Our method achieves 86.19% accuracy on realistic clinical data while maintaining 75.27% accuracy when transferring between different environments - a 12% improvement over existing methods. When used to augment markerless personnel tracking, our approach improves accuracy by over 50%, addressing failure modes including occlusions and personnel re-entering the operating room. Through extensive validation across three datasets and the introduction of a novel workflow visualization technique, we demonstrate how our framework can reveal novel insights into surgical team dynamics and space utilization patterns, advancing methods to analyze surgical workflows and team coordination.
Tony Danjun Wang, Lennart Bastian, Tobias Czempiel, Christian Heiliger, Nassir Navab
Medical Image Anal.2
2024 Hybrid Functional Maps for Crease-Aware Non-Isometric Shape Matching
abstract
Non-isometric shape correspondence remains a fundamental challenge in computer vision. Traditional methods using Laplace-Beltrami operator (LBO) eigenmodes face limitations in characterizing high-frequency extrinsic shape changes like bending and creases. We propose a novel approach of combining the non-orthogonal extrinsic basis of eigenfunctions of the elastic thin-shell hessian with the intrinsic ones of the LBO, creating a hybrid spectral space in which we construct functional maps. To this end, we present a theoretical framework to effectively integrate non-orthogonal basis functions into descriptor- and learning-based functional map methods. Our approach can be in-corporated easily into existing functional map pipelines across varying applications and can handle complex de-formations beyond isometries. We show extensive evaluations across various supervised and unsupervised settings and demonstrate significant improvements. Notably, our approach achieves up to 15% better mean geodesic error for non-isometric correspondence settings and up to 45% improvement in scenarios with topological noise. Code is available at: https://hybridfmaps.github.io/
Lennart Bastian, Yizheng Xie, Nassir Navab, Zorah Lähner
CVPR1
2023 S3M: Scalable Statistical Shape Modeling Through Unsupervised Correspondences
Lennart Bastian, Alex Baumann, Emily Hoppe, Vincent Bürgin, Ha Young Kim, Mahdi Saleh, Benjamin Busam, Nassir Navab
MICCAI (10)1
2023 SegmentOR: Obtaining Efficient Operating Room Semantics Through Temporal Propagation
Lennart Bastian, Daniel Derkacz-Bogner, Tony Danjun Wang, Benjamin Busam, Nassir Navab
MICCAI (9)1