object surface
Recently Published Documents


TOTAL DOCUMENTS

268
(FIVE YEARS 48)

H-INDEX

16
(FIVE YEARS 2)

2022 ◽  
Vol 41 (2) ◽  
pp. 1-17
Author(s):  
Giacomo Nazzaro ◽  
Enrico Puppo ◽  
Fabio Pellacini

Tangles are complex patterns, which are often used to decorate the surface of real-world artisanal objects. They consist of arrangements of simple shapes organized into nested hierarchies, obtained by recursively splitting regions to add progressively finer details. In this article, we show that 3D digital shapes can be decorated with tangles by working interactively in the intrinsic metric of the surface. Our tangles are generated by the recursive application of only four operators, which are derived from tracing the isolines or the integral curves of geodesics fields generated from selected seeds on the surface. Based on this formulation, we present an interactive application that lets designers model complex recursive patterns directly on the object surface without relying on parametrization. We reach interactive speed on meshes of a few million triangles by relying on an efficient approximate graph-based geodesic solver.


2021 ◽  
pp. 1-24
Author(s):  
Rajesh Kumar ◽  
Sudipto Mukherjee

Abstract An algorithm to search for a kinematically desired robotic grasp pose with rolling contacts is presented. A manipulability measure is defined to characterise the grasp for multi-fingered robotic handling. The methodology can be used to search for the goal grasp pose with a manipulability ellipsoid close to the desired one. The proposed algorithm is modified to perform rolling based relocation under kinematic constraints of the robotic fingertips. The search for the optimal grasp pose and the improvement of the grasp pose by relocation is based on the reduction of the geodesic distance between the current and the target manipulability matrices. The algorithm also derives paths of the fingertip on the object surface in order to achieve the goal pose. An algorithmic option for the process of searching for a suitable grasp configuration is hence achieved.


2021 ◽  
Author(s):  
S. Mizushima ◽  
H. Kudo ◽  
Y. Dobashi ◽  
Y. Mizokami

The appearance of an object depends on its material, shape, and lighting. In particular, the diffuseness of the illumination has a significant effect on the appearance of material and surface texture. We investigated a diffuseness condition suitable for reproducing surface appearance using computer graphics. First, observers memorized the appearance and impression of objects by viewing pre-observation images rendered using various environment maps. Then they evaluated the appearance of the objects in test images rendered under different levels of diffuseness. As a result, moderate diffuseness conditions received a higher evaluation than low diffuseness conditions. This means that low or very high diffuseness unfamiliar in daily life is unsuitable for reproducing a faithful and ideal surface appearance. However, a particular material is difficult to memorize and evaluate its appearance. The results suggest that it is possible to define a diffuseness that adequately reproduces the appearance of an object using computer graphics.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Wenli Mao ◽  
Bingyu Zhang

The traditional art education model often cannot achieve good teaching results due to the development of digital technology. Art is integrated with technology based on three-dimensional (3D) panoramic vision sensing technology, so as to study the application of the combination of visual sensing technology and digital image art in the field of art education. With the application of projection virtual game “Whac-A-Mole” as an example, the integration of panoramic color volume structured light generation technology with single emission point and omnidirectional visual imaging technology with single view is proposed; the mathematical model of the active vision system is established, and the camera model, projector model, object surface illumination model, and their relationship are studied. On this basis, the mathematical relationship between the color of the projected light source and the color of the corresponding imaging point is proposed; a light source color correction algorithm based on the two-color reflection model is proposed. The object surface color is corrected by three-channel reflectance after the light source color correction algorithm is used for correction. The results suggest that the 3D panoramic vision sensing technology makes the current active stereo vision develop from the visual perception of surface structure to the visual perception of volume structure and reduces the error rate of recognition from 44% to 11%. Moreover, the algorithm does not need to know the coding method of the projected light source and the surface material of the object in advance. The scene teaching combined with technology overcomes the limitations of the teaching site and brings students into a completely realistic teaching situation. The presentation of digital image art using visual sensing technology can inspire children’s imagination, combine education and games, and perform edutainment. Thereby, the application research of digital image art based on 3D panoramic visual sensing technology has an irreplaceable development prospect in the field of art education.


2021 ◽  
Vol 2091 (1) ◽  
pp. 012002
Author(s):  
Elena Stoykova ◽  
Dimana Nazarova ◽  
Lian Nedelchev ◽  
Mikhail Levchenko ◽  
Nataliya Berberova-Buhova ◽  
...  

Abstract The paper is dedicated to analysis of normalized intensity-based pointwise algorithms for processing dynamic speckle images with spatially varying speckle statistics in non-destructive visualization of regions of faster or slower changes across an object. Both existing and newly proposed algorithms are analyzed. Extraction of speed of changes is done by acquiring correlated in time speckle images formed on the object surface under laser illumination. The studied algorithms have been applied to simulated low and high contrast speckle data. Their performance has been compared to processing of binary patterns as another approach for dealing with varying speckle statistics in the acquired images. The efficiency of the algorithms have been checked on the experimental data, including data in a compressed format. We have proven that the algorithms with normalization at successive instants by a sum of two intensities or a single intensity outperform as a whole the algorithms which apply the time-averaged estimates of the mean value and the variance of speckle intensity.


2021 ◽  
Vol 850 (1) ◽  
pp. 012029
Author(s):  
Vaishnav Madhavadas ◽  
Dibyarup Das ◽  
Kaustubh Anand Mohta ◽  
S. Senthur Prabu

Abstract Fins are widely used to enhance the amount of heat transfer by improving the rate of convection heat transfer. Fins are also known as extended surfaces, i.e., extrusions from the object surface. There are numerous kinds of fins, and based on the shape and size, the amount of heat transfer through the fins will differ. Heat transfer depends upon the geometry of the fin and depends upon a number of factors such as the nature of the fin surface, the ambient temperature; the velocity of the air, etc. In this present study, the systematic review is carried out by critically analyzing the different types of fin profile such as plain rectangular fin, wavy fin, circular pin fin, and rectangular pin fin to increase the fins efficiency. The outcome from this study reveals that the heat transferred by the fins is mainly dependent on the fins profile (type and shape), length, angle, and surface area. Alongside the orientation of the fins, porosity, thermo-geometry also affects the fins’ efficiency.


Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6680
Author(s):  
Min-Jae Lee ◽  
Gi-Mun Um ◽  
Joungil Yun ◽  
Won-Sik Cheong ◽  
Soon-Yong Park

In this paper, we propose a multi-view stereo matching method, EnSoft3D (Enhanced Soft 3D Reconstruction) to obtain dense and high-quality depth images. Multi-view stereo is one of the high-interest research areas and has wide applications. Motivated by the Soft3D reconstruction method, we introduce a new multi-view stereo matching scheme. The original Soft3D method is introduced for novel view synthesis, while occlusion-aware depth is also reconstructed by integrating the matching costs of the Plane Sweep Stereo (PSS) and soft visibility volumes. However, the Soft3D method has an inherent limitation because the erroneous PSS matching costs are not updated. To overcome this limitation, the proposed scheme introduces an update process of the PSS matching costs. From the object surface consensus volume, an inverse consensus kernel is derived, and the PSS matching costs are iteratively updated using the kernel. The proposed EnSoft3D method reconstructs a highly accurate 3D depth image because both the multi-view matching cost and soft visibility are updated simultaneously. The performance of the proposed method is evaluated by using structured and unstructured benchmark datasets. Disparity error is measured to verify 3D reconstruction accuracy, and both PSNR and SSIM are measured to verify the simultaneous enhancement of view synthesis.


Sign in / Sign up

Export Citation Format

Share Document