4 research outputs found
Story-to-Motion: Synthesizing Infinite and Controllable Character Animation from Long Text
Generating natural human motion from a story has the potential to transform
the landscape of animation, gaming, and film industries. A new and challenging
task, Story-to-Motion, arises when characters are required to move to various
locations and perform specific motions based on a long text description. This
task demands a fusion of low-level control (trajectories) and high-level
control (motion semantics). Previous works in character control and
text-to-motion have addressed related aspects, yet a comprehensive solution
remains elusive: character control methods do not handle text description,
whereas text-to-motion methods lack position constraints and often produce
unstable motions. In light of these limitations, we propose a novel system that
generates controllable, infinitely long motions and trajectories aligned with
the input text. (1) We leverage contemporary Large Language Models to act as a
text-driven motion scheduler to extract a series of (text, position, duration)
pairs from long text. (2) We develop a text-driven motion retrieval scheme that
incorporates motion matching with motion semantic and trajectory constraints.
(3) We design a progressive mask transformer that addresses common artifacts in
the transition motion such as unnatural pose and foot sliding. Beyond its
pioneering role as the first comprehensive solution for Story-to-Motion, our
system undergoes evaluation across three distinct sub-tasks: trajectory
following, temporal action composition, and motion blending, where it
outperforms previous state-of-the-art motion synthesis methods across the
board. Homepage: https://story2motion.github.io/.Comment: 8 pages, 6 figure
SynBody: Synthetic Dataset with Layered Human Models for 3D Human Perception and Modeling
Synthetic data has emerged as a promising source for 3D human research as it
offers low-cost access to large-scale human datasets. To advance the diversity
and annotation quality of human models, we introduce a new synthetic dataset,
SynBody, with three appealing features: 1) a clothed parametric human model
that can generate a diverse range of subjects; 2) the layered human
representation that naturally offers high-quality 3D annotations to support
multiple tasks; 3) a scalable system for producing realistic data to facilitate
real-world tasks. The dataset comprises 1.2M images with corresponding accurate
3D annotations, covering 10,000 human body models, 1,187 actions, and various
viewpoints. The dataset includes two subsets for human pose and shape
estimation as well as human neural rendering. Extensive experiments on SynBody
indicate that it substantially enhances both SMPL and SMPL-X estimation.
Furthermore, the incorporation of layered annotations offers a valuable
training resource for investigating the Human Neural Radiance Fields (NeRF).Comment: Accepted by ICCV 2023. Project webpage: https://synbody.github.io
Study on Galloping Oscillation of Iced Twin Bundle Conductors considering the Effects of Variation of Aerodynamic and Electromagnetic Forces
Due to the occurrence of whole-span and subspan vibration at the same time during the galloping of the iced bundle conductors, the distance between the subconductors changes, resulting in the variation of the aerodynamic parameters for the leeward subconductors. The existing conventional studies usually only consider the whole-span galloping, ignoring the relative motion and the electromagnetic force between the subconductors. Based on considering the above two factors at the same time, a new numerical simulation method to study the galloping behaviors of the iced conductors is presented. Then, the galloping behaviors of the iced twin bundle conductors’ transmission line with different current intensity, initial wind attack angle, and spacer layout are studied. The galloping oscillation behaviors include time histories of vibration displacements, mode, amplitude, frequency, motion traces, and the distance between two subconductors. The simulation results showed that the whole-span and subspan vibration appear at the same time during galloping oscillation and two subconductors may collide with each other when affected by the varying electromagnetic and aerodynamic forces. The effects of varying electromagnetic and aerodynamic forces on galloping behavior cannot be ignored. The new method presented in this work can contribute to the galloping study of the iced bundle conductors
Atomic Replacement of PtNi Nanoalloys within Zn-ZIF‑8 for the Fabrication of a Multisite CO<sub>2</sub> Reduction Electrocatalyst
Exploring the transformation/interconversion pathways
of catalytic
active metal species (single atoms, clusters, nanoparticles) on a
support is crucial for the fabrication of high-efficiency catalysts,
the investigation of how catalysts are deactivated, and the regeneration
of spent catalysts. Sintering and redispersion represent the two main
transformation modes for metal active components in heterogeneous
catalysts. Herein, we established a novel solid-state atomic replacement
transformation for metal catalysts, through which metal atoms exchanged
between single atoms and nanoalloys to form a new set of nanoalloys
and single atoms. Specifically, we found that the Ni of the PtNi nanoalloy
and the Zn of the ZIF-8-derived Zn1 on nitrogen-doped carbon
(Zn1-CN) experienced metal interchange to produce PtZn
nanocrystals and Ni single atoms (Ni1-CN) at high temperature.
The elemental migration and chemical bond evolution during the atomic
replacement displayed a Ni and Zn mutual migration feature. Density
functional theory calculations revealed that the atomic replacement
was realized by endothermically stretching Zn from the CN support
into the nanoalloy and exothermically trapping Ni with defects on
the CN support. Owing to the synergistic effect of the PtZn nanocrystal
and Ni1-CN, the obtained (PtZn)n/Ni1-CN multisite catalyst showed a lower energy barrier
of CO2 protonation and CO desorption than that of the reference
catalysts in the CO2 reduction reaction (CO2RR), resulting in a much enhanced CO2RR catalytic performance.
This unique atomic replacement transformation was also applicable
to other metal alloys such as PtPd