926 research outputs found
AI-generated Content for Various Data Modalities: A Survey
AI-generated content (AIGC) methods aim to produce text, images, videos, 3D
assets, and other media using AI algorithms. Due to its wide range of
applications and the demonstrated potential of recent works, AIGC developments
have been attracting lots of attention recently, and AIGC methods have been
developed for various data modalities, such as image, video, text, 3D shape (as
voxels, point clouds, meshes, and neural implicit fields), 3D scene, 3D human
avatar (body and head), 3D motion, and audio -- each presenting different
characteristics and challenges. Furthermore, there have also been many
significant developments in cross-modality AIGC methods, where generative
methods can receive conditioning input in one modality and produce outputs in
another. Examples include going from various modalities to image, video, 3D
shape, 3D scene, 3D avatar (body and head), 3D motion (skeleton and avatar),
and audio modalities. In this paper, we provide a comprehensive review of AIGC
methods across different data modalities, including both single-modality and
cross-modality methods, highlighting the various challenges, representative
works, and recent technical directions in each setting. We also survey the
representative datasets throughout the modalities, and present comparative
results for various modalities. Moreover, we also discuss the challenges and
potential future research directions
Data-Driven Shape Analysis and Processing
Data-driven methods play an increasingly important role in discovering
geometric, structural, and semantic relationships between 3D shapes in
collections, and applying this analysis to support intelligent modeling,
editing, and visualization of geometric data. In contrast to traditional
approaches, a key feature of data-driven approaches is that they aggregate
information from a collection of shapes to improve the analysis and processing
of individual shapes. In addition, they are able to learn models that reason
about properties and relationships of shapes without relying on hard-coded
rules or explicitly programmed instructions. We provide an overview of the main
concepts and components of these techniques, and discuss their application to
shape classification, segmentation, matching, reconstruction, modeling and
exploration, as well as scene analysis and synthesis, through reviewing the
literature and relating the existing works with both qualitative and numerical
comparisons. We conclude our report with ideas that can inspire future research
in data-driven shape analysis and processing.Comment: 10 pages, 19 figure
BakedAvatar: Baking Neural Fields for Real-Time Head Avatar Synthesis
Synthesizing photorealistic 4D human head avatars from videos is essential
for VR/AR, telepresence, and video game applications. Although existing Neural
Radiance Fields (NeRF)-based methods achieve high-fidelity results, the
computational expense limits their use in real-time applications. To overcome
this limitation, we introduce BakedAvatar, a novel representation for real-time
neural head avatar synthesis, deployable in a standard polygon rasterization
pipeline. Our approach extracts deformable multi-layer meshes from learned
isosurfaces of the head and computes expression-, pose-, and view-dependent
appearances that can be baked into static textures for efficient rasterization.
We thus propose a three-stage pipeline for neural head avatar synthesis, which
includes learning continuous deformation, manifold, and radiance fields,
extracting layered meshes and textures, and fine-tuning texture details with
differential rasterization. Experimental results demonstrate that our
representation generates synthesis results of comparable quality to other
state-of-the-art methods while significantly reducing the inference time
required. We further showcase various head avatar synthesis results from
monocular videos, including view synthesis, face reenactment, expression
editing, and pose editing, all at interactive frame rates.Comment: ACM Transactions on Graphics (SIGGRAPH Asia 2023). Project Page:
https://buaavrcg.github.io/BakedAvata
3D Face Modelling, Analysis and Synthesis
Human faces have always been of a special interest to researchers in the computer vision and graphics areas. There has been an explosion in the number of studies around accurately modelling, analysing and synthesising realistic faces for various applications. The importance of human faces emerges from the fact that they are invaluable means of effective communication, recognition, behaviour analysis, conveying emotions, etc. Therefore, addressing the automatic visual perception of human faces efficiently could open up many influential applications in various domains, e.g. virtual/augmented reality, computer-aided surgeries, security and surveillance, entertainment, and many more. However, the vast variability associated with the geometry and appearance of human faces captured in unconstrained videos and images renders their automatic analysis and understanding very challenging even today.
The primary objective of this thesis is to develop novel methodologies of 3D computer vision for human faces that go beyond the state of the art and achieve unprecedented quality and robustness. In more detail, this thesis advances the state of the art in 3D facial shape reconstruction and tracking, fine-grained 3D facial motion estimation, expression recognition and facial synthesis with the aid of 3D face modelling. We give a special attention to the case where the input comes from monocular imagery data captured under uncontrolled settings, a.k.a. \textit{in-the-wild} data. This kind of data are available in abundance nowadays on the internet. Analysing these data pushes the boundaries of currently available computer vision algorithms and opens up many new crucial applications in the industry. We define the four targeted vision problems (3D facial reconstruction tracking, fine-grained 3D facial motion estimation, expression recognition, facial synthesis) in this thesis as the four 3D-based essential systems for the automatic facial behaviour understanding and show how they rely on each other. Finally, to aid the research conducted in this thesis, we collect and annotate a large-scale videos dataset of monocular facial performances. All of our proposed methods demonstarte very promising quantitative and qualitative results when compared to the state-of-the-art methods
Neural Radiance Fields: Past, Present, and Future
The various aspects like modeling and interpreting 3D environments and
surroundings have enticed humans to progress their research in 3D Computer
Vision, Computer Graphics, and Machine Learning. An attempt made by Mildenhall
et al in their paper about NeRFs (Neural Radiance Fields) led to a boom in
Computer Graphics, Robotics, Computer Vision, and the possible scope of
High-Resolution Low Storage Augmented Reality and Virtual Reality-based 3D
models have gained traction from res with more than 1000 preprints related to
NeRFs published. This paper serves as a bridge for people starting to study
these fields by building on the basics of Mathematics, Geometry, Computer
Vision, and Computer Graphics to the difficulties encountered in Implicit
Representations at the intersection of all these disciplines. This survey
provides the history of rendering, Implicit Learning, and NeRFs, the
progression of research on NeRFs, and the potential applications and
implications of NeRFs in today's world. In doing so, this survey categorizes
all the NeRF-related research in terms of the datasets used, objective
functions, applications solved, and evaluation criteria for these applications.Comment: 413 pages, 9 figures, 277 citation
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