75,604 research outputs found
MonoNeuralFusion: Online Monocular Neural 3D Reconstruction with Geometric Priors
High-fidelity 3D scene reconstruction from monocular videos continues to be
challenging, especially for complete and fine-grained geometry reconstruction.
The previous 3D reconstruction approaches with neural implicit representations
have shown a promising ability for complete scene reconstruction, while their
results are often over-smooth and lack enough geometric details. This paper
introduces a novel neural implicit scene representation with volume rendering
for high-fidelity online 3D scene reconstruction from monocular videos. For
fine-grained reconstruction, our key insight is to incorporate geometric priors
into both the neural implicit scene representation and neural volume rendering,
thus leading to an effective geometry learning mechanism based on volume
rendering optimization. Benefiting from this, we present MonoNeuralFusion to
perform the online neural 3D reconstruction from monocular videos, by which the
3D scene geometry is efficiently generated and optimized during the on-the-fly
3D monocular scanning. The extensive comparisons with state-of-the-art
approaches show that our MonoNeuralFusion consistently generates much better
complete and fine-grained reconstruction results, both quantitatively and
qualitatively.Comment: 12 pages, 12 figure
SurfelNeRF: Neural Surfel Radiance Fields for Online Photorealistic Reconstruction of Indoor Scenes
Online reconstructing and rendering of large-scale indoor scenes is a
long-standing challenge. SLAM-based methods can reconstruct 3D scene geometry
progressively in real time but can not render photorealistic results. While
NeRF-based methods produce promising novel view synthesis results, their long
offline optimization time and lack of geometric constraints pose challenges to
efficiently handling online input. Inspired by the complementary advantages of
classical 3D reconstruction and NeRF, we thus investigate marrying explicit
geometric representation with NeRF rendering to achieve efficient online
reconstruction and high-quality rendering. We introduce SurfelNeRF, a variant
of neural radiance field which employs a flexible and scalable neural surfel
representation to store geometric attributes and extracted appearance features
from input images. We further extend the conventional surfel-based fusion
scheme to progressively integrate incoming input frames into the reconstructed
global neural scene representation. In addition, we propose a highly-efficient
differentiable rasterization scheme for rendering neural surfel radiance
fields, which helps SurfelNeRF achieve speedups in training and
inference time, respectively. Experimental results show that our method
achieves the state-of-the-art 23.82 PSNR and 29.58 PSNR on ScanNet in
feedforward inference and per-scene optimization settings, respectively.Comment: To appear in CVPR 202
Tracking objects with point clouds from vision and touch
We present an object-tracking framework that fuses point cloud information from an RGB-D camera with tactile information from a GelSight contact sensor. GelSight can be treated as a source of dense local geometric information, which we incorporate directly into a conventional point-cloud-based articulated object tracker based on signed-distance functions. Our implementation runs at 12 Hz using an online depth reconstruction algorithm for GelSight and a modified second-order update for the tracking algorithm. We present data from hardware experiments demonstrating that the addition of contact-based geometric information significantly improves the pose accuracy during contact, and provides robustness to occlusions of small objects by the robot's end effector
On the origin of the C induced reconstruction of Ni(001)
First principles calculations of the geometric and electronic structures have
been performed for two coverages (0.25 ML and 0.5 ML) of C on Ni(001) to
understand the mechanism of the Ni(001) reconstruction induced by carbon
adsorption. The calculated structural behavior of the system is in a good
agreement with experimental observations. The calculated path and energetics of
the -- reconstruction in C/Ni(001) is provided. A
dramatic reduction of the local electronic charge on adsorbed carbon is found
to occur upon the reconstruction that decreases the electron-electron repulsion
on C site. This effect together with the formation of covalent bonds between C
and the second layer Ni atoms, leads to reconstruction of Ni(001).Comment: 11 pages, 7 fugure
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