bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface passivation approaches for silicon, germanium, and III–V semiconductors
Authors: Theeuwes Roel J. , Kessels Wilhelmus M. M. , Macco Bart
Published: November 2024

Semiconductors are key to our modern society, enabling a myriad of fields, including electronics, photovoltaics, and photonics. The performance of semiconductor devices can be significantly hampered by defects occurring at the surfaces and interfaces of the semiconductor. As semiconductor devices continue to be scaled and nanostructuring is becoming more commonplace, such defects are increasingly becoming the limiting factor in the device performance. Surface passivation can be used to reduce the number of defects and improve device performance. However, effective surface passivation approaches and requirements can vary greatly depending on the semiconductor material and the envisioned application. In this review, we aim to bring together the separated fields of research on passivation of various semiconductor materials by drawing parallels and highlighting important differences in these fields. To this end, we focus on passivation of silicon, germanium, gallium arsenide, indium phosphide, and gallium nitride. For silicon, a high-quality interface with few defects is relatively straightforward to obtain, and the remaining defects at the surface can be further passivated by hydrogen. For germanium and III–V semiconductors, it is more challenging to form a high-quality interface, and the role of hydrogen for defect passivation is less clear. Nevertheless, similar surface passivation approaches are used for these various semiconductors, and mainly focus on interface management, involving the use of passivation layers combined with surface treatments and/or interlayers. Understanding and extending the toolbox of semiconductor surface passivation will be of great value for effective passivation of current and future semiconductor devices.
The Signs Were There: Navigating the Challenges of Mental Health in Intercollegiate Athletics
Authors: Watson Ronnie D. , Johnson James E. , Walker Khirey B.
Published: November 2024

Collegiate athletes face pressures that can exacerbate mental health concerns, including suicidal thoughts and behaviors and self-injurious thoughts and behaviors. This case study examines the mental health challenges of Amelia Grace (pseudonym), a Division I collegiate volleyball player, highlighting the complexities of addressing mental health in the high-pressure environment of collegiate sports. The study focuses on Amelia’s mental health challenges, particularly her suicidal thoughts and behaviors and self-injurious thoughts and behaviors within the context of collegiate volleyball, and evaluates the effectiveness of a tailored intervention grounded in existential psychology and the interpersonal theory of suicide. The interpersonal theory of suicide served as the theoretical framework to examine Amelia’s experiences navigating mental health concerns. The intervention strategy combined existential psychological support with cognitive-behavioral techniques, emphasizing the development of coping strategies and existential growth. Amelia’s case illustrates significant mental health challenges compounded by the demands of collegiate volleyball and academic pressures. Notably, the intervention led to improvements in the athlete’s coping skills, a reduction in suicidal thoughts and behaviors and self-injurious thoughts and behaviors, and enhanced overall well-being. The case also highlights the critical role of supportive environments and targeted mental health interventions in collegiate athletics. It emphasizes the need for comprehensive mental health support systems tailored to the challenges athletes face. Through integrating existential psychology with evidence-based practices, the case advocates for systemic changes in collegiate athletic departments to prioritize and enhance mental health.
Goal-Oriented: Crafting a Culturally Resonant Home for FC Cincinnati at TQL Stadium
Authors: Ballouli Khalid , Koesters Todd , Hwang Yongjin
Published: November 2024

This case study presents an intricate narrative that encapsulates the challenges and strategies involved in transitioning FC Cincinnati from the historic Nippert Stadium to the TQL Stadium. Central to this case is Zayn, a strategist in experiential marketing, tasked with ensuring that the club’s essence and established connection with its fan base are not only preserved but enhanced in this new setting. The case details Cincinnati’s rich cultural mosaic, tracing the city’s evolution from its founding in 1788. It highlights the effect of diverse immigrant communities, particularly Germans, on the city’s cultural landscape, including architecture, music, and culinary traditions. This backdrop sets the stage for understanding the significance of FC Cincinnati’s move to a stadium that aims to be more than a sporting venue—a symbol of cultural progress that honors Cincinnati’s history and diversity. Zayn’s challenge lies in reimagining the stadium experience. The case emphasizes the importance of creating a unique, culturally rich stadium environment through sensory branding. Zayn’s unique approach transcends traditional marketing, focusing instead on a culturally branded experience that weaves the local identity, history, and values into the fabric of the stadium, transforming it into a living representation of Cincinnati’s spirit.
Promiscuous Janus kinase binding to cytokine receptors modulates signaling efficiencies and contributes to cytokine pleiotropy
Authors: Zoler Eyal , Meyer Thomas , Bellón Junel Sotolongo , Mönnig Mia , Sun Boyue , Piehler Jacob , Schreiber Gideon
Published: November 2024

Janus kinases (JAKs) bind to class I and II cytokine receptors, activating signaling and regulating gene transcription through signal transducer and activator of transcription (STAT) proteins. Type I interferons (IFNs) require the JAK members TYK2 and JAK1, which bind to the receptor subunits IFNAR1 and IFNAR2, respectively. We investigated the role of JAKs in regulating IFNAR signaling activity. Synthetic IFNARs in which the extracellular domains of IFNAR1 and IFNAR2 are replaced with nanobodies had near-native type I IFN signaling, whereas the homomeric variant of IFNAR2 initiated much weaker signaling, despite harboring docking sites for JAKs and STATs. Cells with JAK1 and TYK2 knockout (KO) showed residual signaling, suggesting partial complementation by the remaining JAKs, particularly when they were overexpressed. Live-cell micropatterning experiments confirmed the promiscuous binding of JAK1, JAK2, and TYK2 to IFNAR1 and IFNAR2, and their recruitment correlated with their relative cellular abundances. However, each JAK had a different efficacy in inducing cross-phosphorylation and downstream signaling. JAK binding was also promiscuous for other cytokine receptors, including IFN-L1, IL-10Rβ, TPOR, and GHR, but not for EPOR, which activated different downstream signaling pathways. These findings suggest that competitive binding of JAKs to cytokine receptors together with the varying absolute and relative abundances of the JAKs in different cell types can account for the cell type–dependent signaling pleiotropy of cytokine receptors.
TYK2 on tau
Authors: Ferrarelli Leslie K.
Published: November 2024

The kinase TYK2 facilitates pathological tau assembly through protein-stabilizing modifications.
Staphylococcus epidermidis
ST2 strains associated with bloodstream infections contain a unique mobile genetic element encoding a plasmin inhibitor
Authors: Gomez Amy A. , Kjerfve Clara , Choi Minseo , Liu Wen , Churion Kelly , Thomas Sheila , Rohde Holger , Shelburne Sam , Skare Jon T. , Hook Magnus , Arora Srishtee
Published: November 2024

Staphylococcus epidermidis
, a common commensal bacterium, is a leading cause of nosocomial catheter-associated bloodstream infections.
S. epidermidis
sequence type 2 (ST2) is specifically recognized globally for causing invasive disease. In this study, we identified a novel putative integrated conjugative element, pICE-Sepi-ST2, unique to the genomes of
S. epidermidis
ST2. Our investigation identified pICE-Sepi-ST2 in all ST2 isolates from bloodstream infections. Meanwhile, ST2 isolates from other infection sources, such as catheters, prosthetic joints, and fracture fixations, showed variable pICE-Sepi-ST2 prevalence. pICE-Sepi-ST2 encodes two putative cell wall anchored proteins that we have designated SesX and SesY. Biochemical characterization of SesY revealed that it binds both plasminogen (Plg) and plasmin (Pln) and inhibits Pln’s ability to cleave a chromogenic substrate and degrade fibrin clots. Furthermore, all ST2 isolates containing a pICE-Sepi-ST2 also have a mutated
sdrG
gene. Thus, all ST2 isolates have two genetic modifications that target distinct steps in the hemostatic pathway. SdrG, which inhibits coagulation, is inactivated, and SesY, which inhibits fibrin, is introduced. These findings suggest that the hemostasis pathway is a strategic target for ST2
S. epidermidis
bloodstream pathogenesis.

IMPORTANCE

This study uncovers a new virulence mechanism in
Staphylococcus epidermidis
ST2 bloodstream isolates. We identify a mobile genetic element (MGE) characteristic of an integrated conjugated element (ICE). pICE-Sepi-ST2 carries the genetic information needed to produce a cell wall-anchored (CWA) protein called SesY. The results indicate that SesY binds to plasminogen (Plg) and plasmin (Pln) and inhibits Pln’s degradation of fibrin clots. Genetic analysis showed that all ST2 bloodstream isolates can express the plasmin inhibitor SesY and carry a mutation in the SdrG gene, resulting in the expression of inactive SdrG. Thus, we describe a molecular pathway targeting the coagulation pathway that may be required for
S. epidermidis
ST2 to cause bloodstream infections.
Tackling the unyielding: testing two novel approaches against NDM-producing Enterobacterales and
Pseudomonas aeruginosa
isolates collected in India
Authors: Bakthavatchalam Yamuna Devi , Behera Bijayini , Shah Anand , Mathur Purva , Ray Raja , Fomda Bashir Ahmed , Walia Kamini , Veeraraghavan Balaji
Published: November 2024

The
in vitro
activity of two novel antibiotics with different modes of action, (i) siderophore cefiderocol and (ii) β-lactam-enhancer mechanism-based cefepime/zidebactam, was tested against New Delhi Metallo-β-lactamase (NDM)-producing Enterobacterales and
Pseudomonas aeruginosa
collected in India. Minimum inhibitory concentrations of antibiotics against multicentric NDM-producing
Escherichia coli
(
n
= 117),
Klebsiella pneumoniae
(
n
= 103), and
P. aeruginosa
(
n
= 72) were determined by the reference broth microdilution method. Among
E. coli
, 111 isolates were NDM-alone, and six were NDM + OXA-48-like producers. Among
K. pneumoniae
, 47 and 56 isolates were NDM-alone and NDM + OXA-48-like producers, respectively. All
E. coli
isolates harbored four amino acid inserts in their penicillin-binding protein 3. Using the highest susceptible breakpoint among CLSI, FDA, and EUCAST interpretive criteria, cefiderocol susceptibility was 39.3%, ≤80%, and 57%, for NDM ± OXA-48-like-producing
E. coli
, NDM ± OXA-48-like-producing
K. pneumoniae,
and NDM-producing
P. aeruginosa
, respectively. At a cefepime break point of ≤8 mg/L, 100% of Enterobacterales and ≥90% of
P. aeruginosa
isolates were cefepime/zidebactam-susceptible. NDM being a dominant carbapenemase among Enterobacterales and
P. aeruginosa
in India, the variable activity of cefiderocol against NDM producers is a concern. Post approval, cefepime/zidebactam could offer a promising treatment option against NDM producers.

IMPORTANCE

Metallo-β-lactamases are therapeutically challenging due to the limited treatment options. Against such isolates, currently approved newer β-lactam/β-lactamase inhibitor combinations are ineffective. In this study, we tested siderophore cephalosporin, cefiderocol, which utilizes an unconventional iron uptake pathway for efficient cellular penetration, and cefepime/zidebactam that utilizes novel β-lactam enhancer mechanisms for overcoming diverse carbapenemases. Cefiderocol showed limited activity against
Escherichia coli
isolates co-harboring New Delhi metallo-β-lactamase (NDM) with PBP3 insert, dual carbapenemase (NDM with OXA-48 like)-producing
Klebsiella pneumoniae
, and NDM-producing
Pseudomonas aeruginosa
isolates, while cefepime/zidebactam potently inhibited NDM-producing Enterobacterales and
P. aeruginosa
isolates. NDM being a dominant carbapenemase among Enterobacterales and
P. aeruginosa
in India, the variable activity of cefiderocol against NDM producers is a concern. Post approval, cefepime/zidebactam could offer a promising treatment option against NDM producers.
Improvement of a MALDI-TOF database for the reliable identification of
Candidozyma auris
(formally
Candida auris
) and related species
Authors: Zhu Hui-Hui , Liu Miao-Miao , Boekhout Teun , Wang Qi-Ming
Published: November 2024

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a promising technique for the rapid identification microorganisms. The aim of this study was to create a new database for the accurate identification of
Candidozyma auris
(formerly known as
Candida auris
) and 11 species of the
Candidozyma haemuli
species complex, including
C. chanthaburiensis
,
C. duobushaemuli
,
C. haemuli
,
C. heveicola
,
C. khanbhai
,
C. konsanensis
,
C. metrosideri
,
C. ohialehuae
,
C. pseudohaemuli
,
C. ruelliae
, and
C. vulturna
. Seventy-one
Candidozyma
isolates from different national institutions were studied. Thirty-seven strains were used to create a MALDI-TOF (microTyper MS) database using the formic acid extraction method. The validation of this database was performed with 34 other strains of the genus
Candidozyma
, and the result was compared with the identification results when using DBRs v1.0.0.4 (Tianrui, China). Our library allowed a 100% identification of the evaluated strains with all strains showing log scores of >2.0. Repeatability and reproducibility tests result showed a coefficient of variation of the log score values of less than 5%. The MALDI-TOF MS system can identify
C. auris
and related species quickly and accurately. This method will play a crucial role in accurately diagnosing infectious agents of the genus
Candidozyma
in clinical practice.

IMPORTANCE

Importance
Candidozyma auris
, also known as
Candida auris
, has quickly spread across the world, and prompt identification of
C. auris
from infected individuals is critical. However, a standard identification method is lacking for the identification of
C. auris
in clinical and public health laboratories. To make matters worse, its biochemical assimilation profile was found to be similar to that of closely related and even no-related species, leading to frequent misidentification. To improve diagnostics of this and closely related species, we created a database of reference mass spectra resulting in the efficient and correct identification of all
Candidozyma
species by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Moreover, potential pathogenic species of
Candidozyma
can be effectively identified by MALDI-TOF MS, and differentiated from non-clinically relevant phylogenetic relatives. Thus, MALDI-TOF MS may help expedite laboratory diagnosis and treatment of
C. auris
and related species of clinical importance and help the clinician to decide on early treatment.
Prior immunity to
Ureaplasma urealyticum
protects against respiratory infection in immunosuppressed mice
Authors: Al-Jabri Maha Y. , Patel Robin , Fleming Derek
Published: November 2024

Ureaplasma
species can cause systemic infections in immunocompromised hosts, including lung transplant recipients. Here, we investigated the impact of prior exposure to
Ureaplasma urealyticum
on the risk of
U. urealyticum
and
Ureaplasma parvum
infection in mice subjected to an immunosuppression regimen similar to that administered to solid organ transplant recipients. Mice were immunized with three intramuscular injections of
U. urealyticum
, with control mice injected with adjuvant only. Following immunization, mice received tacrolimus, mycophenolate mofetil, and methylprednisolone, and then were challenged with
U. urealyticum
or
U. parvum
intraperitoneally and intratracheally over 6 days. Relative
U. urealyticum
antibody levels in plasma were assessed over time, and lungs were harvested at sacrifice for bacterial load quantification, assessed using a color-changing unit assay.
U. urealyticum
antibody levels were higher in immunized compared with control animals (
P
< 0.0001), even when animals were immunosuppressed.
U. urealyticum
and
U. parvum
lung burden was reduced in immunized compared with control mice (~6 log
10
reduction for
U. urealyticum
and <1 log
10
reduction for
U. parvum
;
P
= 0.008 and 0.046, respectively). In summary, this study shows that prior exposure to live
U. urealyticum
provides some protection against infection with
U. urealyticum
.

IMPORTANCE

Ureaplasma
-induced hyperammonemia syndrome is a rare but potentially deadly complication of solid organ transplantation, especially lung transplantation. The pathophysiology of this relatively recently recognized condition is poorly understood, and it is unclear what factors may influence patient susceptibility. This study investigates the possible protective effects of prior exposure to
Ureaplasma urealyticum
in a mouse model subjected to an immunosuppression regimen similar to that given to lung transplant recipients. The findings show that prior exposure could provide protection against
Ureaplasma
lung infection.
Chapter 8. Albertine Rift Fluvial Systems and Terrestrial Rift Valley Environments
Authors: Nicholas Christopher J.
Published: November 2024

Whilst Albertine Rift marginal lacustrine and deltaic depositional environments each produce characteristic lithofacies that together can form a complex stratal architecture, ≥80% of the onshore area of these early continental rift basins is actually dominated by fluvial systems and their associated rift valley terrestrial environments. Albertine Rift rivers today can be classified as flank fan drainage, flank drainage rivers or long-axial systems. Dependent upon slope gradient and sinuosity, and reflecting the bed or suspended load transported, alluvial channels can cycle through four main stages before entering a delta distributary system at the lake shoreline. Higher energy flows closer to rift margins are dominated by gravel bed loads, transitioning to mixed and then suspended loads as gradients decrease out across the rift valley floor. Typical fluvial geomorphological features such as riffle-pool sequences, channel and side bars, meanders, point bars and ox-bow lakes are accompanied by development of characteristic ichno- and rhizo- fabrics in riparian sands and interfluve silts and clays. The four different fluvial stages can be recognized in onshore Pleistocene - Holocene sedimentary successions of both Lake Edward and Lake Albert, with well-sorted fluvial sand bodies, containing termite nests, correlating with petroleum reservoir intervals in the subsurface.
MiNNIE: a Mixed Multigrid Method for Real-time Simulation of Nonlinear Near-Incompressible Elastics
Authors: Ruan Liangwang , Wang Bin , Liu Tiantian , Chen Baoquan
Published: November 2024

We propose MiNNIE, a simple yet comprehensive framework for real-time simulation of nonlinear near-incompressible elastics. To avoid the common volumetric locking issues at high Poisson's ratios of linear finite element methods (FEM), we build MiNNIE upon a mixed FEM framework and further incorporate a pressure stabilization term to ensure excellent convergence of multigrid solvers. Our pressure stabilization strategy injects bounded influence on nodal displacement which can be eliminated using a quasiNewton method. MiNNIE has a specially tailored GPU multigrid solver including a modified skinning-space interpolation scheme, a novel vertex Vanka smoother, and an efficient dense solver using Schur complement. MiNNIE supports various elastic material models and simulates them in real-time, supporting a full range of Poisson's ratios up to 0.5 while handling large deformations, element inversions, and self-collisions at the same time.
GaussianObject: High-Quality 3D Object Reconstruction from Four Views with Gaussian Splatting
Authors: Yang Chen , Li Sikuang , Fang Jiemin , Liang Ruofan , Xie Lingxi , Zhang Xiaopeng , Shen Wei , Tian Qi
Published: November 2024

Reconstructing and rendering 3D objects from highly sparse views is of critical importance for promoting applications of 3D vision techniques and improving user experience. However, images from sparse views only contain very limited 3D information, leading to two significant challenges: 1) Difficulty in building multi-view consistency as images for matching are too few; 2) Partially omitted or highly compressed object information as view coverage is insufficient. To tackle these challenges, we propose GaussianObject, a framework to represent and render the 3D object with Gaussian splatting that achieves high rendering quality with only 4 input images. We first introduce techniques of visual hull and floater elimination, which explicitly inject structure priors into the initial optimization process to help build multi-view consistency, yielding a coarse 3D Gaussian representation. Then we construct a Gaussian repair model based on diffusion models to supplement the omitted object information, where Gaussians are further refined. We design a self-generating strategy to obtain image pairs for training the repair model. We further design a COLMAP-free variant, where pre-given accurate camera poses are not required, which achieves competitive quality and facilitates wider applications. GaussianObject is evaluated on several challenging datasets, including MipNeRF360, OmniObject3D, OpenIllumination, and our-collected unposed images, achieving superior performance from only four views and significantly outperforming previous SOTA methods.
Polarimetric BSSRDF Acquisition of Dynamic Faces
Authors: Ha Hyunho , Hwang Inseung , Monzon Nestor , Cho Jaemin , Kim Donggun , Baek Seung-Hwan , Muñoz Adolfo , Gutierrez Diego , Kim Min H.
Published: November 2024

Acquisition and modeling of polarized light reflection and scattering help reveal the shape, structure, and physical characteristics of an object, which is increasingly important in computer graphics. However, current polarimetric acquisition systems are limited to static and opaque objects. Human faces, on the other hand, present a particularly difficult challenge, given their complex structure and reflectance properties, the strong presence of spatially-varying subsurface scattering, and their dynamic nature. We present a new polarimetric acquisition method for dynamic human faces, which focuses on capturing spatially varying appearance and precise geometry, across a wide spectrum of skin tones and facial expressions. It includes both single and heterogeneous subsurface scattering, index of refraction, and specular roughness and intensity, among other parameters, while revealing biophysically-based components such as inner- and outer-layer hemoglobin, eumelanin and pheomelanin. Our method leverages such components' unique multispectral absorption profiles to quantify their concentrations, which in turn inform our model about the complex interactions occurring within the skin layers. To our knowledge, our work is the first to simultaneously acquire polarimetric and spectral reflectance information alongside biophysically-based skin parameters and geometry of dynamic human faces. Moreover, our polarimetric skin model integrates seamlessly into various rendering pipelines.
Computational Biomimetics of Winged Seeds
Authors: Le Qiqin , Bu Jiamu , Qu Yanke , Zhu Bo , Du Tao
Published: November 2024

We develop a computational pipeline to facilitate the biomimetic design of winged seeds. Our approach leverages 3D scans of natural winged seeds to construct a bio-inspired design space by interpolating them with geodesic coordinates in the 3D diffeomorphism group. We formulate aerodynamic design tasks with probabilistic performance objectives and adapt a gradient-free optimizer to explore the design space and minimize the expectation of performance objectives efficiently and effectively. Our pipeline discovers novel winged seed designs that outperform natural counterparts in aerodynamic tasks, including long-distance dispersal and guided flight. We validate the physical fidelity of our pipeline by showcasing paper models of selected winged seeds in the design space and reporting their similar aerodynamic behaviors in simulation and reality.
Volumetric Homogenization for Knitwear Simulation
Authors: Yuan Chun , Shi Haoyang , Lan Lei , Qiu Yuxing , Yuksel Cem , Wang Huamin , Jiang Chenfanfu , Wu Kui , Yang Yin
Published: November 2024

This paper presents volumetric homogenization, a spatially varying homogenization scheme for knitwear simulation. We are motivated by the observation that macro-scale fabric dynamics is strongly correlated with its underlying knitting patterns. Therefore, homogenization towards a single material is less effective when the knitting is complex and non-repetitive. Our method tackles this challenge by homogenizing the yarn-level material locally at volumetric elements. Assigning a virtual volume of a knitting structure enables us to model bending and twisting effects via a simple volume-preserving penalty and thus effectively alleviates the material nonlinearity. We employ an adjoint Gauss-Newton formulation[Zehnder et al. 2021] to battle the dimensionality challenge of such per-element material optimization. This intuitive material model makes the forward simulation GPU-friendly. To this end, our pipeline also equips a novel domain-decomposed subspace solver crafted for GPU projective dynamics, which makes our simulator hundreds of times faster than the yarn-level simulator. Experiments validate the capability and effectiveness of volumetric homogenization. Our method produces realistic animations of knitwear matching the quality of full-scale yarn-level simulations. It is also orders of magnitude faster than existing homogenization techniques in both the training and simulation stages.
Particle-Laden Fluid on Flow Maps
Authors: Li Zhiqi , Chen Duowen , Lin Candong , Liu Jinyuan , Zhu Bo
Published: November 2024

We propose a novel framework for simulating ink as a particle-laden flow using particle flow maps. Our method addresses the limitations of existing flow-map techniques, which struggle with dissipative forces like viscosity and drag, thereby extending the application scope from solving the Euler equations to solving the Navier-Stokes equations with accurate viscosity and laden-particle treatment. Our key contribution lies in a coupling mechanism for two particle systems, coupling physical sediment particles and virtual flow-map particles on a background grid by solving a Poisson system. We implemented a novel path integral formula to incorporate viscosity and drag forces into the particle flow map process. Our approach enables state-of-the-art simulation of various particle-laden flow phenomena, exemplified by the bulging and breakup of suspension drop tails, torus formation, torus disintegration, and the coalescence of sedimenting drops. In particular, our method delivered high-fidelity ink diffusion simulations by accurately capturing vortex bulbs, viscous tails, fractal branching, and hierarchical structures.
Representing Long Volumetric Video with Temporal Gaussian Hierarchy
Authors: Xu Zhen , Xu Yinghao , Yu Zhiyuan , Peng Sida , Sun Jiaming , Bao Hujun , Zhou Xiaowei
Published: November 2024

This paper aims to address the challenge of reconstructing long volumetric videos from multi-view RGB videos. Recent dynamic view synthesis methods leverage powerful 4D representations, like feature grids or point cloud sequences, to achieve high-quality rendering results. However, they are typically limited to short (1~2s) video clips and often suffer from large memory footprints when dealing with longer videos. To solve this issue, we propose a novel 4D representation, named Temporal Gaussian Hierarchy, to compactly model long volumetric videos. Our key observation is that there are generally various degrees of temporal redundancy in dynamic scenes, which consist of areas changing at different speeds. Motivated by this, our approach builds a multi-level hierarchy of 4D Gaussian primitives, where each level separately describes scene regions with different degrees of content change, and adaptively shares Gaussian primitives to represent unchanged scene content over different temporal segments, thus effectively reducing the number of Gaussian primitives. In addition, the tree-like structure of the Gaussian hierarchy allows us to efficiently represent the scene at a particular moment with a subset of Gaussian primitives, leading to nearly constant GPU memory usage during the training or rendering regardless of the video length. Moreover, we design a Compact Appearance Model that mixes diffuse and view-dependent Gaussians to further minimize the model size while maintaining the rendering quality. We also develop a rasterization pipeline of Gaussian primitives based on the hardware-accelerated technique to improve rendering speed. Extensive experimental results demonstrate the superiority of our method over alternative methods in terms of training cost, rendering speed, and storage usage. To our knowledge, this work is the first approach capable of efficiently handling hours of volumetric video data while maintaining state-of-the-art rendering quality.
PCO: Precision-Controllable Offset Surfaces with Sharp Features
Authors: Wang Lei , Wang Xudong , Wang Pengfei , Chen Shuangmin , Xin Shiqing , Guo Jiong , Wang Wenping , Tu Changhe
Published: November 2024

Surface offsetting is a crucial operation in digital geometry processing and computer-aided design, where an offset is defined as an iso-value surface of the distance field. A challenge emerges as even smooth surfaces can exhibit sharp features in their offsets due to the non-differentiable characteristics of the underlying distance field. Prevailing approaches to the offsetting problem involve approximating the distance field and then extracting the iso-surface. However, even with dual contouring (DC), there is a risk of degrading sharp feature points/lines due to the inaccurate discretization of the distance field. This issue is exacerbated when the input is a piecewise-linear triangle mesh.

This study is inspired by the observation that a triangle-based distance field, unlike the complex distance field rooted at the entire surface, remains smooth across the entire 3D space except at the triangle itself. With a polygonal surface comprising
n
triangles, the final distance field for accommodating the offset surface is determined by minimizing these
n
triangle-based distance fields. In implementation, our approach starts by tetrahedralizing the space around the offset surface, enabling a tetrahedron-wise linear approximation for each triangle-based distance field. The final offset surface within a tetrahedral range can be traced by slicing the tetrahedron with planes. As illustrated in the teaser figure, a key advantage of our algorithm is its ability to precisely preserve sharp features. Furthermore, this paper addresses the problem of simplifying the offset surface's complexity while preserving sharp features, formulating it as a maximal-clique problem.
GFFE: G-buffer Free Frame Extrapolation for Low-latency Real-time Rendering
Authors: Wu Songyin , Vembar Deepak , Sochenov Anton , Panneer Selvakumar , Kim Sungye , Kaplanyan Anton , Yan Ling-Qi
Published: November 2024

Real-time rendering has been embracing ever-demanding effects, such as ray tracing. However, rendering such effects in high resolution and high frame rate remains challenging. Frame extrapolation methods, which do not introduce additional latency as opposed to frame interpolation methods such as DLSS 3 and FSR 3, boost the frame rate by generating future frames based on previous frames. However, it is a more challenging task because of the lack of information in the disocclusion regions and complex future motions, and recent methods also have a high engine integration cost due to requiring G-buffers as input. We propose a
G-buffer free
frame extrapolation method, GFFE, with a novel heuristic framework and an efficient neural network, to plausibly generate new frames in real time without introducing additional latency. We analyze the motion of dynamic fragments and different types of disocclusions, and design the corresponding modules of the extrapolation block to handle them. After that, a light-weight shading correction network is used to correct shading and improve overall quality. GFFE achieves comparable or better results than previous interpolation and G-buffer dependent extrapolation methods, with more efficient performance and easier integration.
DARTS: Diffusion Approximated Residual Time Sampling for Time-of-flight Rendering in Homogeneous Scattering Media
Authors: He Qianyue , Du Dongyu , Jiang Haitian , Jin Xin
Published: November 2024

Time-of-flight (ToF) devices have greatly propelled the advancement of various multi-modal perception applications. However, achieving accurate rendering of time-resolved information remains a challenge, particularly in scenes involving complex geometries, diverse materials and participating media. Existing ToF rendering works have demonstrated notable results, yet they struggle with scenes involving scattering media and camera-warped settings. Other steady-state volumetric rendering methods exhibit significant bias or variance when directly applied to ToF rendering tasks. To address these challenges, we integrate transient diffusion theory into path construction and propose novel sampling methods for free-path distance and scattering direction, via resampled importance sampling and offline tabulation. An elliptical sampling method is further adapted to provide controllable vertex connection satisfying any required photon traversal time. In contrast to the existing temporal uniform sampling strategy, our method is the first to consider the contribution of transient radiance to importance-sample the full path, and thus enables improved temporal path construction under multiple scattering settings. The proposed method can be integrated into both path tracing and photon-based frameworks, delivering significant improvements in quality and efficiency with at least a 5x MSE reduction versus SOTA methods in equal rendering time.
Learning Based Toolpath Planner on Diverse Graphs for 3D Printing
Authors: Huang Yuming , Guo Yuhu , Su Renbo , Han Xingjian , Ding Junhao , Zhang Tianyu , Liu Tao , Wang Weiming , Fang Guoxin , Song Xu , Whiting Emily , Wang Charlie
Published: November 2024

This paper presents a learning based planner for computing optimized 3D printing toolpaths on prescribed graphs, the challenges of which include the varying graph structures on different models and the large scale of nodes & edges on a graph. We adopt an on-the-fly strategy to tackle these challenges, formulating the planner as a
Deep Q-Network
(DQN) based optimizer to decide the next 'best' node to visit. We construct the state spaces by the
Local Search Graph
(LSG) centered at different nodes on a graph, which is encoded by a carefully designed algorithm so that LSGs in similar configurations can be identified to re-use the earlier learned DQN priors for accelerating the computation of toolpath planning. Our method can cover different 3D printing applications by defining their corresponding reward functions. Toolpath planning problems in wire-frame printing, continuous fiber printing, and metallic printing are selected to demonstrate its generality. The performance of our planner has been verified by testing the resultant toolpaths in physical experiments. By using our planner, wire-frame models with up to 4.2k struts can be successfully printed, up to 93.3% of sharp turns on continuous fiber toolpaths can be avoided, and the thermal distortion in metallic printing can be reduced by 24.9%.
3D Gaussian Ray Tracing: Fast Tracing of Particle Scenes
Authors: Moenne-Loccoz Nicolas , Mirzaei Ashkan , Perel Or , de Lutio Riccardo , Martinez Esturo Janick , State Gavriel , Fidler Sanja , Sharp Nicholas , Gojcic Zan
Published: November 2024

Particle-based representations of radiance fields such as 3D Gaussian Splatting have found great success for reconstructing and re-rendering of complex scenes. Most existing methods render particles via rasterization, projecting them to screen space tiles for processing in a sorted order. This work instead considers ray tracing the particles, building a bounding volume hierarchy and casting a ray for each pixel using high-performance GPU ray tracing hardware. To efficiently handle large numbers of semi-transparent particles, we describe a specialized rendering algorithm which encapsulates particles with bounding meshes to leverage fast ray-triangle intersections, and shades batches of intersections in depth-order. The benefits of ray tracing are well-known in computer graphics: processing incoherent rays for secondary lighting effects such as shadows and reflections, rendering from highly-distorted cameras common in robotics, stochastically sampling rays, and more. With our renderer, this flexibility comes at little cost compared to rasterization. Experiments demonstrate the speed and accuracy of our approach, as well as several applications in computer graphics and vision. We further propose related improvements to the basic Gaussian representation, including a simple use of generalized kernel functions which significantly reduces particle hit counts.
Direct Manipulation of Procedural Implicit Surfaces
Authors: Riso Marzia , Michel Élie , Paris Axel , Deschaintre Valentin , Gaillard Mathieu , Pellacini Fabio
Published: November 2024

Procedural implicit surfaces are a popular representation for shape modeling. They provide a simple framework for complex geometric operations such as Booleans, blending and deformations. However, their editability remains a challenging task: as the definition of the shape is purely implicit, direct manipulation of the shape cannot be performed. Thus, parameters of the model are often exposed through abstract sliders, which have to be nontrivially created by the user and understood by others for each individual model to modify. Further, each of these sliders needs to be set one by one to achieve the desired appearance. To circumvent this laborious process while preserving editability, we propose to directly manipulate the implicit surface in the viewport. We let the user naturally interact with the output shape, leveraging points on a co-parameterization we design specifically for implicit surfaces, to guide the parameter updates and reach the desired appearance faster. We leverage our automatic differentiation of the procedural implicit surface to propagate interactions made by the user in the viewport to the shape parameters themselves. We further design a solver that uses such information to guide an intuitive and smooth user workflow. We demonstrate different editing processes across multiple implicit shapes and parameters that would be tedious by tuning sliders.
Gaussian Opacity Fields: Efficient Adaptive Surface Reconstruction in Unbounded Scenes
Authors: Yu Zehao , Sattler Torsten , Geiger Andreas
Published: November 2024

Recently, 3D Gaussian Splatting (3DGS) has demonstrated impressive novel view synthesis results, while allowing the rendering of high-resolution images in real-time. However, leveraging 3D Gaussians for surface reconstruction poses significant challenges due to the explicit and disconnected nature of 3D Gaussians. In this work, we present Gaussian Opacity Fields (GOF), a novel approach for efficient, high-quality, and adaptive surface reconstruction in unbounded scenes. Our GOF is derived from ray-tracing-based volume rendering of 3D Gaussians, enabling direct geometry extraction from 3D Gaussians by identifying its levelset, without resorting to Poisson reconstruction or TSDF fusion as in previous work. We approximate the surface normal of Gaussians as the normal of the ray-Gaussian intersection plane, enabling the application of regularization that significantly enhances geometry. Furthermore, we develop an efficient geometry extraction method utilizing Marching Tetrahedra, where the tetrahedral grids are induced from 3D Gaussians and thus adapt to the scene's complexity. Our evaluations reveal that GOF surpasses existing 3DGS-based methods in surface reconstruction and novel view synthesis. Further, it compares favorably to or even outperforms, neural implicit methods in both quality and speed.
Quad mesh mechanisms
Authors: Jiang Caigui , Lyakhov Dmitry , Rist Florian , Pottmann Helmut , Wallner Johannes
Published: November 2024

This paper provides computational tools for the modeling and design of quad mesh mechanisms, which are meshes allowing continuous flexions under the assumption of rigid faces and hinges in the edges. We combine methods and results from different areas, namely differential geometry of surfaces, rigidity and flexibility of bar and joint frameworks, algebraic geometry, and optimization. The basic idea to achieve a time-continuous flexion is time-discretization justified by an algebraic degree argument. We are able to prove computationally feasible bounds on the number of required time instances we need to incorporate in our optimization. For optimization to succeed, an informed initialization is crucial. We present two computational pipelines to achieve that: one based on remeshing isometric surface pairs, another one based on iterative refinement. A third manner of initialization proved very effective: We interactively design meshes which are close to a narrow known class of flexible meshes, but not contained in it. Having enjoyed sufficiently many degrees of freedom during design, we afterwards optimize towards flexibility.
UFO Instruction Graphs Are Machine Knittable
Authors: Lin Jenny Han , Ikarashi Yuka , Bernstein Gilbert Louis , McCann James
Published: November 2024

Programming low-level controls for knitting machines is a meticulous, time-consuming task that demands specialized expertise. Recently, there has been a shift towards automatically generating low-level knitting machine programs from high-level knit representations that describe knit objects in a more intuitive, user-friendly way. Current high-level systems trade off expressivity for ease-of-use, requiring ad-hoc trapdoors to access the full space of machine capabilities, or eschewing completeness in the name of utility. Thus, advanced techniques either require ad-hoc extensions from domain experts, or are entirely unsupported. Furthermore, errors may emerge during the compilation from knit object representations to machine instructions. While the generated program may describe a valid machine control sequence, the fabricated object is topologically different from the specified input, with little recourse for understanding and fixing the issue.

To address these limitations, we introduce
instruction graphs
, an intermediate representation capable of capturing the full range of machine knitting programs. We define a semantic mapping from instruction graphs to fenced tangles, which make them compatible with the established formal semantics for machine knitting instructions. We establish a semantics-preserving bijection between machine knittable instruction graphs and knit programs that proves three properties - upward, forward, and ordered (UFO) - are both necessary and sufficient to ensure the existence of a machine knitting program that can fabricate the fenced tangle denoted by the graph. As a proof-of-concept, we implement an instruction graph editor and compiler that allows a user to transform an instruction graph into UFO presentation and then compile it to a machine program, all while maintaining semantic equivalence. In addition, we use the UFO properties to more precisely characterize the limitations of existing compilers. This work lays the groundwork for more expressive and reliable automated knitting machine programming systems by providing a formal characterization of machine knittability.
Enhancing the Aesthetics of 3D Shapes via Reference-based Editing
Authors: Chen Minchan , Lau Manfred
Published: November 2024

While there have been previous works that explored methods to enhance the aesthetics of images, the automated beautification of 3D shapes has been limited to specific shapes such as 3D face models. In this paper, we introduce a framework to automatically enhance the aesthetics of general 3D shapes. Our approach employs a reference-based beautification strategy. We first performed data collection to gather the aesthetics ratings of various 3D shapes to create a 3D shape aesthetics dataset. Then we perform reference-based editing to edit the input shape and beautify it by making it look more like some reference shape that is aesthetic. Specifically, we propose a reference-guided global deformation framework to coherently deform the input shape such that its structural proportions will be closer to those of the reference shape. We then optionally transplant some local aesthetic parts from the reference to the input to obtain the beautified output shapes. Comparisons show that our reference-guided 3D deformation algorithm outperforms existing techniques. Furthermore, quantitative and qualitative evaluations demonstrate that the performance of our aesthetics enhancement framework is consistent with both human perception and existing 3D shape aesthetics assessment.
Fluid Implicit Particles on Coadjoint Orbits
Authors: Nabizadeh Mohammad Sina , Roy-Chowdhury Ritoban , Yin Hang , Ramamoorthi Ravi , Chern Albert
Published: November 2024

We propose Coadjoint Orbit FLIP (CO-FLIP), a high order accurate, structure preserving fluid simulation method in the hybrid Eulerian-Lagrangian framework. We start with a Hamiltonian formulation of the incompressible Euler Equations, and then, using a local, explicit, and high order divergence free interpolation, construct a modified Hamiltonian system that governs our discrete Euler flow. The resulting discretization, when paired with a geometric time integration scheme, is energy and circulation preserving (formally the flow evolves on a coadjoint orbit) and is similar to the Fluid Implicit Particle (FLIP) method. CO-FLIP enjoys multiple additional properties including that the pressure projection is exact in the weak sense, and the particle-to-grid transfer is an exact inverse of the grid-to-particle interpolation. The method is demonstrated numerically with outstanding stability, energy, and Casimir preservation. We show that the method produces benchmarks and turbulent visual effects even at low grid resolutions.