16,091 research outputs found

    The Simulation of the Brush Stroke Based on Force Feedback Technology

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    A novel simulation method of the brush stroke is proposed by applying force feedback technology to the virtual painting process. The relationship between force and the brush deformation is analyzed, and the spring-mass model is applied to construct the brush model, which can realistically simulate the brush morphological changes according to the force exerted on it. According to the deformation of the brush model at a sampling point, the brush footprint between the brush and the paper is calculated in real time. Then, the brush stroke is obtained by superimposing brush footprints along sampling points, and the dynamic painting of the brush stroke is implemented. The proposed method has been successfully applied to the virtual painting system based on the force feedback technology. In this system, users can implement the painting in real time with a Phantom Desktop haptic device, which can effectively enhance reality to users

    Volumetric cloud generation using a Chinese brush calligraphy style

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    Includes bibliographical references.Clouds are an important feature of any real or simulated environment in which the sky is visible. Their amorphous, ever-changing and illuminated features make the sky vivid and beautiful. However, these features increase both the complexity of real time rendering and modelling. It is difficult to design and build volumetric clouds in an easy and intuitive way, particularly if the interface is intended for artists rather than programmers. We propose a novel modelling system motivated by an ancient painting style, Chinese Landscape Painting, to address this problem. With the use of only one brush and one colour, an artist can paint a vivid and detailed landscape efficiently. In this research, we develop three emulations of a Chinese brush: a skeleton-based brush, a 2D texture footprint and a dynamic 3D footprint, all driven by the motion and pressure of a stylus pen. We propose a hybrid mapping to generate both the body and surface of volumetric clouds from the brush footprints. Our interface integrates these components along with 3D canvas control and GPU-based volumetric rendering into an interactive cloud modelling system. Our cloud modelling system is able to create various types of clouds occurring in nature. User tests indicate that our brush calligraphy approach is preferred to conventional volumetric cloud modelling and that it produces convincing 3D cloud formations in an intuitive and interactive fashion. While traditional modelling systems focus on surface generation of 3D objects, our brush calligraphy technique constructs the interior structure. This forms the basis of a new modelling style for objects with amorphous shape

    Volumetric Cloud Rendering: An Animation of Clouds

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    This paper demonstrates a production workflow for a volumetric-rendering-based short animation about clouds. The animation is based on the concept of a giant fish swimming in the sky from Zhuangzi\u27s philosophical story. The algorithm and implementation for the modeling and rendering of clouds are also presented. A renderer was developed that uses the OpenVDB library for data storage, fast retrieving and grid manipulation. A user-friendly pipeline was also developed for cloud modeling and rendering, which used Python and XML for adjusting rendering parameters. The pipeline includes Maya to build the rough cloud model and Houdini to calculate the interior light points. Final compositing was done in Nuke. Several MEL and Python scripts were also used to retrieve camera and light information from Maya and Houdini, thereby facilitating the production process

    A study of how Chinese ink painting features can be applied to 3D scenes and models in real-time rendering

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    Past research findings addressed mature techniques for non-photorealistic rendering. However, research findings indicate that there is little information dealing with efficient methods to simulate Chinese ink painting features in rendering 3D scenes. Considering that Chinese ink painting has achieved many worldwide awards, the potential to effectively and automatically develop 3D animations and games in this style indicates a need for the development of appropriate technology for the future market. The goal of this research is about rendering 3D meshes in a Chinese ink painting style which is both appealing and realistic. Specifically, how can the output image appear similar to a hand-drawn Chinese ink painting. And how efficient does the rendering pipeline have to be to result in a real-time scene. For this study the researcher designed two rendering pipelines for static objects and moving objects in the final scene. The entire rendering process includes interior shading, silhouette extracting, textures integrating, and background rendering. Methodology involved the use of silhouette detection, multiple rendering passes, Gaussian blur for anti-aliasing, smooth step functions, and noise textures for simulating ink textures. Based on the output of each rendering pipeline, rendering process of the scene with best looking of Chinese ink painting style is illustrated in detail. The speed of the rendering pipeline proposed by this research was tested. The framerate of the final scenes created with this pipeline was higher than 30fps, a level considered to be real-time. One can conclude that the main objective of the research study was met even though other methods for generating Chinese ink painting rendering are available and should be explored

    Correlation between Grafting Density and Confined Crystallization Behavior of Poly(ethylene glycol) Grafted to Silica

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    The interfacial interactions of polymer-nanoparticles have dramatical effects on the crystallization behavior of grafted polymers. In this study, methoxy polyethylene glycol (MPEG) (molecular weights 750, 2000 and 4000 g mol−1) was grafted onto amino-modified nanosized silica (SiO2-NH2) by the “grafting to” method. The effects of the grafting density and molecular weight on the confined crystallization of grafted MPEG (MPEG-g-SiO2) were systematically investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and wide-angle X-ray scattering (WAXS). It was found that confinement effects are stronger when lower molecular weights of grafted MPEG are employed. These grafted MPEG chains are more difficult to stretch out on SiO2-NH2 surfaces than when they are free in the bulk polymer. Both crystallization temperature (Tc) and crystallinity of grafted MPEG chains decrease with reductions of grafting density. Additionally, covalent bonding effects and interfacial interaction confinement effects are strengthened by the decrease in grafting density, leading to an increase in decomposition temperature and to the disappearance of the self-nucleation Domain (i.e., Domain II), when self-nucleation experiments are performed by DSC. Overall isothermal crystallization kinetics was studied by DSC and the results were analyzed with the Avrami equation. An Avrami index of n≈3 was obtained for neat MPEG (indicating that instantaneous spherulites are formed). However, in the case of MPEG-g-SiO2 with the lowest grafting density, the Avrami index of (n) was less than 1 (first order kinetics or lower), indicating that nucleation is the determining factor of the overall crystallization kinetics, a signature for confined crystallization. At the same time, the crystallization from the melt for this MPEG-g-SiO2 with the lowest grafting density occurs at Tc ≈-30 ÂșC, a temperature close to the glass transition temperature (Tg) of MPEG, indicating that this confined MPEG crystallizes from homogeneous nuclei.This project was supported by the National Natural Science Foundation of China (21574141) and the Ministry of Science and Technology of China (2017YFE0117800). The authors gratefully acknowledge the funding of project BIODEST, Research and Innovation Staff Exchange (RISE) H2020-MSCA-RISE-2017-778092. The authors thank beamline BL16B1 (Shanghai Synchrotron Radiation Facility) for providing the beam time and helps during experiments

    Art Directed Watercolor Shader for Non-photorealistic Rendering with a Focus on Reflections

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    In this research, I demonstrated that emulating painterly reflections is impossible using existing modeling, compositing and rendering software that does not provide programming capabilities. To obtain painterly reflections, we need to emulate three aspects of painterly reflections: (1) shape of reflections; (2) glossiness of reflections; and (3) colors of reflections. The first two turn out to be relatively easy. However, despite the perceived simplicity of color reproduction, the third one turned out to be hardest without developing our own proprietary tools. To demonstrate the difficulty, I have developed a shader using commercial rendering and shading software that does not provide explicit programming power. I assigned my shader as a surface material to 3D objects. Using my shader, I was able to create computer generated watercolor style renderings without reflections. My shader provide rendering effects such as diffuse, contours, specularity, shadow, and reflections. Although I can faithfully emulate non-reflected regions of given water-color paintings, I demonstrate that my shader cannot produce reflection colors that are faithful to colors of original reflections

    Simple, low-cost solar pumping is now a reality

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    A breakthrough has been achieved in making small solar pumps affordable and easy to set up and use by small farmers in Africa. Numerous off-the-shelf pumps running on direct current were tested when connected directly to a single solar panel, without any battery or additional electronics. Of the many pump models tested, two were found to meet our criteria for low-cost solar pumping for small-scale irrigation. These pumps have been successfully operating in Cameroon, Chad, Burkina Faso, Senegal and Canada since 2014. We present information on the components, cost and performance of these pumps for small-scale irrigation

    A multimodal approach looking at the cultural significance of a festival : a unit of work for young learners of Chinese in a NSW school

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    This research explores the potential effects of a multimodal approach on motivating young learners’ Chinese learning in Australian primary schools. The study’s main research question was: How can different modes be combined to motivate Chinese learning within an Australian primary school context? The contributory research question was: How can a teacher-researcher integrate their knowledge as a native speaker with the knowledge of local teachers to design a unit of work for primary school students using a multimodal pedagogy? The teacher-researcher was a bilingual volunteer teacher of the Research-Oriented School-Engaged Teacher Education program. She was provided the opportunity to teach in a local school and implement research for its students. However, due to the COVID-19 pandemic, this study was conducted through online interviews via Zoom meetings with two experienced teachers about a unit of work based on the theme of the Dragon Boat Festival. The research method was a qualitative case study. Research data was mainly collected from the two interviewees’ feedback and the teacher-researcher’s reflective journal. Based on the findings generated from the data, visual-auditory and kinesthetic-visual are the two types of combined modes for Chinese acquisition. These modes are combined to interpret Chinese for students based on the linguistic features of the Chinese language and the characteristics of targeted young learners who are energetic in doing movements and keen on interesting images. Further, this study found two main teaching strategies for novice teachers to motivate students’ language learning under a multimodal approach. One is getting students to realise their responsibility in language learning, and the other is making an effort to find teaching materials related to students’ daily life and the topics they like
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