A comparison of hole-filling methods in 3D

This paper presents a review of the most relevant current techniques that deal with hole-filling in 3D models. Contrary to earlier reports, which approach mesh repairing in a sparse and global manner, the objective of this review is twofold. First, a specific and comprehensive review of hole-filling techniques (as a relevant part in the field of mesh repairing) is carried out. We present a brief summary of each technique with attention paid to its algorithmic essence, main contributions and limitations. Second, a solid comparison between 34 methods is established. To do this, we define 19 possible meaningful features and properties that can be found in a generic hole-filling process. Then, we use these features to assess the virtues and deficiencies of the method and to build comparative tables. The purpose of this review is to make a comparative hole-filling state-of-the-art available to researchers, showing pros and cons in a common framework.• Ministerio de Economía y Competitividad: Proyecto DPI2013-43344-R (I+D+i) • Gobierno de Castilla-La Mancha: Proyecto PEII-2014-017-PpeerReviewe

Réalité Augmentée et Environnement Collaboratif : Un Tour d'Horizon

National audienceLa Réalité Augmentée (RA) est généralement définie comme une branche dérivée de la Réalité Virtuelle. D'une façon plus générale, le concept de réalité augmentée regroupe une approche multidisciplinaire visant un mélange entre réel et virtuel. La forte potentialité induite par cette connexion promet un cadre adéquat pour l'interaction 3D ou les applications collaboratives. On présente dans cet article un tour d'horizon des principaux travaux menés à ce jour dans le cadre de l'image et de la RA et plus particulièrement le cadre collaboratif

XOR-Based Compact Triangulations

Media, image processing, and geometric-based systems and applications need data structures to model and represent different geometric entities and objects. These data structures have to be time efficient and compact in term of space. Many structures in use are proposed to satisfy those constraints. This paper introduces a novel compact data structure inspired by the XOR-linked lists. The subject of this paper concerns the triangular data structures. Nevertheless, the underlying idea could be used for any other geometrical subdivision. The ability of the bitwise XOR operator to reduce the number of references is used to model triangle and vertex references. The use of the XOR combined references needs to define a context from which the triangle is accessed. The direct access to any triangle is not possible using only the XOR-linked scheme. To allow the direct access, additional information are added to the structure. This additional information permits a constant time access to any element of the triangulation using a local resolution scheme. This information represents an additional cost to the triangulation, but the gain is still maintained. This cost is reduced by including this additional information to a local sub-triangulation and not to each triangle. Sub-triangulations are calculated implicitly according to the catalog-based structure. This approach could be easily extended to other representation models, such as vertex-based structures or edge-based structures. The obtained results are very interesting since the theoretical gain is estimated to 38 % and the practical gain obtained from sample benches is about 34 %

From Capture to Display: A Survey on Volumetric Video

Volumetric video, which offers immersive viewing experiences, is gaining increasing prominence. With its six degrees of freedom, it provides viewers with greater immersion and interactivity compared to traditional videos. Despite their potential, volumetric video services poses significant challenges. This survey conducts a comprehensive review of the existing literature on volumetric video. We firstly provide a general framework of volumetric video services, followed by a discussion on prerequisites for volumetric video, encompassing representations, open datasets, and quality assessment metrics. Then we delve into the current methodologies for each stage of the volumetric video service pipeline, detailing capturing, compression, transmission, rendering, and display techniques. Lastly, we explore various applications enabled by this pioneering technology and we present an array of research challenges and opportunities in the domain of volumetric video services. This survey aspires to provide a holistic understanding of this burgeoning field and shed light on potential future research trajectories, aiming to bring the vision of volumetric video to fruition.Comment: Submitte

3D Virtual Worlds and the Metaverse: Current Status and Future Possibilities

Moving from a set of independent virtual worlds to an integrated network of 3D virtual worlds or Metaverse rests on progress in four areas: immersive realism, ubiquity of access and identity, interoperability, and scalability. For each area, the current status and needed developments in order to achieve a functional Metaverse are described. Factors that support the formation of a viable Metaverse, such as institutional and popular interest and ongoing improvements in hardware performance, and factors that constrain the achievement of this goal, including limits in computational methods and unrealized collaboration among virtual world stakeholders and developers, are also considered

TangiPaint: Interactive tangible media

Currently, there is a wide disconnection between the real and virtual worlds in computer graphics. Art created with textured paints on canvases have visual effects which naturally supplement simple color. Real paint exhibits shadows and highlights, which change in response to viewing and lighting directions. The colors interact with this environment and can produce very noticeable effects. Additionally, the traditional means of human-computer interaction using a keyboard and mouse is unnatural and inefficient---gestures and actions are not performed on the objects themselves. These visual effects and natural interactions are missing from digital media in the virtual world. The absence of these visual characteristics disconnects users from their content. Our research looks into simulating these missing pieces and reconnecting users. TangiPaint is an interactive, tangible application for creating and exploring digital media. It gives the experience of working with real materials, such as oil paints and textured canvases, on a digital display. TangiPaint implements natural gestures and allows users to directly interact with their work. The Tangible Display technology allows users to tilt and reorient the device and screen to see the subtle gloss, shadow, and impasto lighting effects of the simulated surface. To simulate realistic lighting effects we use a Ward BRDF illumination model. This model is implemented as an OpenGL shader program. Our system tracks the texture and relief of a piece of art by saving topographical information. We implement height fields, normal vectors, and parameter maps to store this information. These textures are submitted to the lighting model that renders a final product. TangiPaint builds on previous work and applications in this area, but is the first to integrate these aspects into a single software application. The system is entirely self-contained and implemented on the Apple iOS platforms, the iPhone, iPad, and iPod Touch. No additional hardware is required and the interface is easy to learn and use. TangiPaint is a step in the direction of interactive digital art media that looks and behaves like real materials

Resolution independent curved seams in clothing animation using a regular particle grid

We present a method for representing seams in clothing animation, and its application in simulation level of detail. Specifically we consider cloth represented as a regular grid of particles connected by spring-dampers, and a seam specified by a closed set of parametric trim curves in the cloth domain. Conventional cloth animation requires the tessellation of seams so that they are handled uniformly by the dynamics process. Our goal is a seam definition which does not constrain the attached clothing panels to be of the same resolution, or even constant resolution, while not being a hindrance to the dynamics process. We also apply our seams to cloth defined on a regular grid, as opposed to the irregular meshes commonly used with seams. The determination of particles interior to the cloth panel can be done using wellknown graphics operations such as scan-conversion. Due to the particle-based nature of the simulation, the dynamics approach combines easily with existing implicit and explicit methods. Finally, because the seams are resolution independent, the particle density per clothing panel can be adjusted as desired. This gives rise to a simple application of the given seams approach illustrating how it may be used for simulation level of detail