Computer Animation and Virtual Worlds最新文献

Stylized animation strives for innovation and bold visual creativity. Integrating the inherent strong visual impact and color contrast of woodcut style into such animations is both appealing and challenging, especially during the design phase. Traditional woodcut methods, hand-drawing, and previous computer-aided techniques face challenges such as dwindling design inspiration, lengthy production times, and complex adjustment procedures. To address these issues, we propose a novel network framework, the Woodcut-style Design Assistant Network (WDANet). Our research is the first to use diffusion models to streamline the woodcut-style design process. We curate the Woodcut-62 dataset, which features works from 62 renowned historical artists, to train WDANet in capturing and learning the aesthetic nuances of woodcut prints. WDANet, based on the denoising U-Net, effectively decouples content and style features. It allows users to input or slightly modify a text description to quickly generate accurate, high-quality woodcut-style designs, saving time and offering flexibility. Quantitative and qualitative analyses, along with user studies, confirm that WDANet outperforms current state-of-the-art methods in generating woodcut-style images, demonstrating its value as a design aid.

Neural radiance fields (NeRF) technology has garnered significant attention due to its exceptional performance in generating high-quality novel view images. In this study, we propose an innovative method that leverages the similarity between views to enhance the quality of novel view image generation. Initially, a pre-trained NeRF model generates an initial novel view image, which is subsequently compared and subjected to feature transfer with the most similar reference view from the training dataset. Following this, the reference view that is most similar to the initial novel view is selected from the training dataset. We designed a texture transfer module that employs a strategy progressing from coarse-to-fine, effectively integrating salient features from the reference view into the initial image, thus producing more realistic novel view images. By using similar views, this approach not only improves the quality of novel perspective images but also incorporates the training dataset as a dynamic information pool into the novel view integration process. This allows for the continuous acquisition and utilization of useful information from the training data throughout the synthesis process. Extensive experimental validation shows that using similar views to provide scene information significantly outperforms existing neural rendering techniques in enhancing the realism and accuracy of novel view images.

Semantic segmentation is an important approach to present the perceptual semantic understanding of an image, which is of significant usage in various applications. Especially, body part segmentation is designed for segmenting body parts of human characters to assist different editing tasks, such as style editing, pose transfer, and animation production. Since segmentation requires pixel-level precision in semantic labeling, classic heuristics-based methods generally have unstable performance. With the deployment of deep learning, a great step has been taken in segmenting body parts of human characters in natural photographs. However, the existing models are purely trained on natural photographs and generally obtain incorrect segmentation results when applied on anime character images, due to the large visual gap between training data and testing data. In this article, we present a novel approach to achieving body part segmentation of cartoon characters via a pose-based graph-cut formulation. We demonstrate the use of the acquired body part segmentation map in various image editing tasks, including conditional generation, style manipulation, pose transfer, and video-to-anime.

Urban 3D models with high-resolution details are the basis of various mixed reality and geographic information systems. Fast and accurate urban reconstruction from aerial photographs has attracted intense attention. Existing methods exploit multi-view geometry information from landscape patterns with similar illumination conditions and terrain appearance. In practice, urban models become obsolete over time due to human activities. Mainstream reconstruction pipelines rebuild the whole scene even if the main part of them remains unchanged. This paper proposes a novel wrapping-based incremental modeling framework to reuse existing models and renew them with new meshes efficiently. The paper illustrates a pose optimization method with illumination-based augmentation and virtual bundle adjustment. Besides, a high-performance wrapping-based meshing method is proposed for fast reconstruction. Experimental results show that the proposed method can achieve higher performance and quality than state-of-the-art methods.

A challenge in crowd simulation is to generate diverse pedestrian motions in virtual environments. Nowadays, there is a greater emphasis on the diversity and authenticity of pedestrian movements in crowd simulation, while most traditional models primarily focus on collision avoidance and motion continuity. Recent studies have enhanced realism through data-driven approaches that exploit the movement patterns of pedestrians from real data for trajectory prediction. However, they have not taken into account the body-part motions of pedestrians. Differing from these approaches, we innovatively utilize learning-based character motion and physics animation to enhance the diversity of pedestrian motions in crowd simulation. The proposed method can provide a promising avenue for more diverse crowds and is realized by a novel framework that deeply integrates motion synthesis and physics animation with crowd simulation. The framework consists of three main components: the learning-based motion generator, which is responsible for generating diverse character motions; the hybrid simulation, which ensures the physical realism of pedestrian motions; and the velocity-based interface, which assists in integrating navigation algorithms with the motion generator. Experiments have been conducted to verify the effectiveness of the proposed method in different aspects. The visual results demonstrate the feasibility of our approach.

Conducting research on this subject remains relevant in light of the rapid development of technology and the emergence of new threats in cybersecurity, requiring constant updating of knowledge and protection methods. The purpose of the study is to identify effective front-end security methods and technologies that help ensure the protection of user data and their privacy when using web applications or sites. A methodology that defines the steps and processes for effective front-end security and user data protection is developed. The research identifies the primary security threats, including cross-site scripting (XSS), cross-site request forgery (CSRF), and SQL injections, and evaluates existing front-end security methods such as Content Security Policy (CSP), HTTPS, authentication, and authorization mechanisms. The findings highlight the effectiveness of these measures in mitigating security risks, providing a clear assessment of their advantages and limitations. Key recommendations for developers include the integration of modern security protocols, regular updates, and comprehensive security training. This study offers practical insights to improve front-end security and enhance user data protection in an evolving digital landscape.

With the digital protection and development of cultural heritage as a focus, an analysis of the trends in cultural heritage digitization reveals the importance of digital technology in this field, as demonstrated by the application of virtual reality (VR) to the protection and development of the Lingjiatan site. The implementation of the Lingjiatan roaming system involves sequential steps, including image acquisition, image splicing, and roaming system production. A user test was conducted to evaluate the usability and user experience of the system. The results show that the system operates normally, with smooth interactive functions that allow users to tour the Lingjiatan site virtually. Users can learn about Lingjiatan's culture from this virtual environment. This study further explores the system's potential for site preservation and development, and its role in the integration of cultural heritage and tourism.

Painting is a complex and creative process that involves the use of various drawing skills to create artworks. The concept of training artificial intelligence models to imitate this process is referred to as neural painting. To enable ordinary people to engage in the process of painting, we propose PainterAR, a novel interface that renders any paintings stroke-by-stroke in an immersive and realistic augmented reality (AR) environment. PainterAR is composed of two components: the neural painting model and the AR interface. Regarding the neural painting model, unlike previous models, we introduce the Kullback–Leibler divergence to replace the original Wasserstein distance existed in the baseline paint transformer model, which solves an important problem of encountering different scales of strokes (big or small) during painting. We then design an interactive AR interface, which allows users to upload an image and display the creation process of the neural painting model on the virtual drawing board. Experiments demonstrate that the paintings generated by our improved neural painting model are more realistic and vivid than previous neural painting models. The user study demonstrates that users prefer to control the painting process interactively in our AR environment.

This work proposes a novel approach to transform any modern game engine pipeline, for optimized performance and enhanced user experiences in extended reality (XR) environments decoupling the physics engine from the game engine pipeline and using a client-server $��N�-�1�$ architecture creates a scalable solution, efficiently serving multiple graphics clients on head-mounted displays (HMDs) with a single physics engine on edge-cloud infrastructure. This approach ensures better synchronization in multiplayer scenarios without introducing overhead in single-player experiences, maintaining session continuity despite changes in user participation. Relocating the Physics Engine to an edge or cloud node reduces strain on local hardware, dedicating more resources to high-quality rendering and unlocking the full potential of untethered HMDs. We present four algorithms that decouple the physics engine, increasing frame rates and Quality of Experience (QoE) in VR simulations, supporting advanced interactions, numerous physics objects, and multiuser sessions with over 100 concurrent users. Incorporating a Geometric Algebra interpolator reduces inter-calls between dissected parts, maintaining QoE and easing network stress. Experimental validation, with more than 100 concurrent users, 10,000 physics objects, and softbody simulations, confirms the technical viability of the proposed architecture, showcasing transformative capabilities for more immersive and collaborative XR applications without compromising performance.