As 3D technology, including computer graphics, virtual reality and 3D printing, has been rapidly developed in the past years, 3D models are gaining an increasingly huge demand. Traditional 3D modeling platforms such a...As 3D technology, including computer graphics, virtual reality and 3D printing, has been rapidly developed in the past years, 3D models are gaining an increasingly huge demand. Traditional 3D modeling platforms such as Maya and ZBrush, utilize ＂windows, icons, menus, pointers＂ （WlMP） interface paradigms for fine-grained control to construct detailed models. However, the modeling progress can be tedious and frustrating and thus too hard for a novice user or even a well trained artist. Therefore, a more intuitive interface is needed. Sketch, an intuitive communication and modeling tool for human beings, becomes the first choice of modeling community. So far, various sketch-based modeling systems have been created and studied. In this paper, we at- tempt to show how these systems work and give a comprehensive survey. We review and categorize the systems in four aspects： the input, the knowledge they use, the modeling approach and the output. We also discuss about inherent challenges and open problems for researchers in the future.展开更多
This paper presents Symm Sketch—a system for creating symmetric 3D free-form shapes from 2D sketches. The reconstruction task usually separates a 3D symmetric shape into two types of shape components, that is, the se...This paper presents Symm Sketch—a system for creating symmetric 3D free-form shapes from 2D sketches. The reconstruction task usually separates a 3D symmetric shape into two types of shape components, that is, the self-symmetric shape component and the mutual-symmetric shape components. Each type can be created in an intuitive manner. Using a uniform symmetry plane, the user first draws 2D sketch lines for each shape component on a sketching plane. The z-depth information of the hand-drawn input sketches can be calculated using their property of mirror symmetry to generate 3D construction curves. In order to provide more freedom for controlling the local geometric features of the reconstructed free-form shapes(e.g., non-circular crosssections), our modeling system creates each shape component from four construction curves. Using one pair of symmetric curves and one pair of general curves, an improved cross-sectional surface blending scheme is applied to generate a parametric surface for each component. The final symmetric free-form shape is progressively created, and is represented by 3D triangular mesh. Experimental results illustrate that our system can generate complex symmetric free-form shapes effectively and conveniently.展开更多
This paper presents a new approach for modeling a virtual garment intuitively and simply by sketching garment style lines.The user sketches directly onto the surface of 3D virtual human from arbitrary viewing directio...This paper presents a new approach for modeling a virtual garment intuitively and simply by sketching garment style lines.The user sketches directly onto the surface of 3D virtual human from arbitrary viewing directions,and the 3D garment suited to the virtual human can be created automatically.First,a distance field based allocation algorithm is proposed to find the 3D point which has the shortest given distance to the virtual human along the view direction.Then,the 3D style lines are generated by transforming from the 2D strokes on the human model and all the garment pieces are recognized from the 3D style lines.Finally,the 3D garment model is constructed by using the angle and offset based interpolation and Delaunay triangulation.In addition,we propose a body feature based template reusing method to fit the 3D garment to different virtual human models.The method can be adapted to designer habits and improve the usefulness of garment design.Examples show that the method is useful and efficient.展开更多
3D model retrieval virtual reality applications. In can benefit many downstream this paper, we propose a new sketch-based 3D model retrieval framework by coupling local features and manifold ranking. At technical fron...3D model retrieval virtual reality applications. In can benefit many downstream this paper, we propose a new sketch-based 3D model retrieval framework by coupling local features and manifold ranking. At technical fronts, we exploit spatial pyramids based local structures to facilitate the efficient construction of feature descriptors. Meanwhile, we propose an improved manifold ranking method, wherein all the categories between arbitrary model pairs will be taken into account. Since the smooth and detail-preserving line drawings of 3D model are important for sketch-based 3D model retrieval, the Difference of Gaussians （DOG） method is employed to extract the line drawings over the projected depth images of 3D model, and Bezier Curve is then adopted to further optimize the extracted line drawing. On that basis, we develop a 3D model retrieval engine to verify our method. We have conducted extensive experiments over various public benchmarks, and have made comprehensive comparisons with some state-of-the-art 3D retrieval methods. All the evaluation results based on the widely-used indicators prove the superiority of our method in accuracy, reliability, robustness, and versatility.展开更多
With the rapid development of Web3 D technologies, sketch-based model retrieval has become an increasingly important challenge, while the application of Virtual Reality and 3 D technologies has made shape retrieval of...With the rapid development of Web3 D technologies, sketch-based model retrieval has become an increasingly important challenge, while the application of Virtual Reality and 3 D technologies has made shape retrieval of furniture over a web browser feasible. In this paper, we propose a learning framework for shape retrieval based on two Siamese VGG-16 Convolutional Neural Networks(CNNs), and a CNN-based hybrid learning algorithm to select the best view for a shape. In this algorithm, the AlexNet and VGG-16 CNN architectures are used to perform classification tasks and to extract features, respectively. In addition, a feature fusion method is used to measure the similarity relation of the output features from the two Siamese networks. The proposed framework can provide new alternatives for furniture retrieval in the Web3 D environment. The primary innovation is in the employment of deep learning methods to solve the challenge of obtaining the best view of 3 D furniture,and to address cross-domain feature learning problems. We conduct an experiment to verify the feasibility of the framework and the results show our approach to be superior in comparison to many mainstream state-of-the-art approaches.展开更多
Large-scale dynamic relational data visualization has attracted considerable research attention recently. We introduce dynamic data visualization into the multimedia domain, and present an interactive and scalable sys...Large-scale dynamic relational data visualization has attracted considerable research attention recently. We introduce dynamic data visualization into the multimedia domain, and present an interactive and scalable system, Video Map, for exploring large-scale video content. A long video or movie has much content; the associations between the content are complicated. Video Map uses new visual representations to extract meaningful information from video content. Map-based visualization naturally and easily summarizes and reveals important features and events in video. Multi-scale descriptions are used to describe the layout and distribution of temporal information, spatial information, and associations between video content. Firstly, semantic associations are used in which map elements correspond to video contents. Secondly, video contents are visualized hierarchically from a large scale to a fine-detailed scale. Video Map uses a small set of sketch gestures to invoke analysis, and automatically completes charts by synthesizing visual representations from the map and binding them to the underlying data. Furthermore,Video Map allows users to use gestures to move and resize the view, as when using a map, facilitating interactive exploration. Our experimental evaluation of Video Map demonstrates how the system can assist in exploring video content as well as significantly reducing browsing time when trying to understand and find events of interest.展开更多
Character models have enormous applications in industry.Efficient creation of detailed character models is an important topic.This paper proposes a new and easy-to-use technique to quickly create detailed character mo...Character models have enormous applications in industry.Efficient creation of detailed character models is an important topic.This paper proposes a new and easy-to-use technique to quickly create detailed character models from sketches.The proposed technique consists of two main components:primitive deformer and shape generators.With this technique,2D silhouette contours of a character model are drawn or extracted from an image or sketch.Then,proper geometric primitives are selected and aligned with the corresponding 2D silhouette contours.After that,a primitive deformer is used to create a base mesh and three shape generators are used to add 3D details to the base mesh.The primitive deformer and three shape generators are developed from ODE-driven deformations.The primitive deformer deforms the aligned geometric primitives to exactly match the 2D silhouette contours in one view plane and obtains a base mesh of a character model consisting of deformed primitives.The shape generators are used to add 3D details to the base mesh by creating local 3D models.The experimental results demonstrate that the new technique can quickly create detailed 3D character models from sketches with few manual operations.The new technique is physics-based and easy to learn and use.展开更多
A novel and fast shape classification and regularization algorithm for on-line sketchy graphics recognition is proposed. We divide the on-line graphics recognition process into four stages: preprocessing,shape classif...A novel and fast shape classification and regularization algorithm for on-line sketchy graphics recognition is proposed. We divide the on-line graphics recognition process into four stages: preprocessing,shape classification,shape fitting,and regularization. Attraction Force Model is employed to progressively combine the vertices on the input sketchy stroke and reduce the total number of vertices before the type of shape can be determined. After that ,the shape is fitted and gradually rectified to a regular one,thus the regularized shape fits the user intended one precisely.Experimental results show that this algorithm can yield good recognition precision(averagely above 90% )and fine regularization effect but with fast speed. Consequently,it is especially suitable to computational critical environment such as PDAs,which solely depends on a pen-based user interface.展开更多
文摘As 3D technology, including computer graphics, virtual reality and 3D printing, has been rapidly developed in the past years, 3D models are gaining an increasingly huge demand. Traditional 3D modeling platforms such as Maya and ZBrush, utilize ＂windows, icons, menus, pointers＂ （WlMP） interface paradigms for fine-grained control to construct detailed models. However, the modeling progress can be tedious and frustrating and thus too hard for a novice user or even a well trained artist. Therefore, a more intuitive interface is needed. Sketch, an intuitive communication and modeling tool for human beings, becomes the first choice of modeling community. So far, various sketch-based modeling systems have been created and studied. In this paper, we at- tempt to show how these systems work and give a comprehensive survey. We review and categorize the systems in four aspects： the input, the knowledge they use, the modeling approach and the output. We also discuss about inherent challenges and open problems for researchers in the future.
基金supported by the National Natural Science Foundation of China under Grant Nos. 61272309 and 61303138
文摘This paper presents Symm Sketch—a system for creating symmetric 3D free-form shapes from 2D sketches. The reconstruction task usually separates a 3D symmetric shape into two types of shape components, that is, the self-symmetric shape component and the mutual-symmetric shape components. Each type can be created in an intuitive manner. Using a uniform symmetry plane, the user first draws 2D sketch lines for each shape component on a sketching plane. The z-depth information of the hand-drawn input sketches can be calculated using their property of mirror symmetry to generate 3D construction curves. In order to provide more freedom for controlling the local geometric features of the reconstructed free-form shapes(e.g., non-circular crosssections), our modeling system creates each shape component from four construction curves. Using one pair of symmetric curves and one pair of general curves, an improved cross-sectional surface blending scheme is applied to generate a parametric surface for each component. The final symmetric free-form shape is progressively created, and is represented by 3D triangular mesh. Experimental results illustrate that our system can generate complex symmetric free-form shapes effectively and conveniently.
基金Project supported by the National High-Tech R & D Program (863) of China (No. 2009AA04Z103)the Project of Public Technology Research in Industry (No. 2010C31001)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China (No. 20100101110025)the Natural Science Foundation of Ningbo City,China (No.2010A610117)
文摘This paper presents a new approach for modeling a virtual garment intuitively and simply by sketching garment style lines.The user sketches directly onto the surface of 3D virtual human from arbitrary viewing directions,and the 3D garment suited to the virtual human can be created automatically.First,a distance field based allocation algorithm is proposed to find the 3D point which has the shortest given distance to the virtual human along the view direction.Then,the 3D style lines are generated by transforming from the 2D strokes on the human model and all the garment pieces are recognized from the 3D style lines.Finally,the 3D garment model is constructed by using the angle and offset based interpolation and Delaunay triangulation.In addition,we propose a body feature based template reusing method to fit the 3D garment to different virtual human models.The method can be adapted to designer habits and improve the usefulness of garment design.Examples show that the method is useful and efficient.
基金The authors would like to thank Zhang Dongdong for his great help in experiments. This work was supported by the National Natural Science Foundation of China （Grant No. 61602324）, the Scientific Research Project of Beijing Educational Committeen （KM201710028018）, the open funding project of State Key Laboratory of Virtual Reality Technology and Systems, Beihang University （BUAA-VR-17KF-12） and Beijing Advanced Innovation Center for Imaging Technology （BAlCIT-2016004）.
文摘3D model retrieval virtual reality applications. In can benefit many downstream this paper, we propose a new sketch-based 3D model retrieval framework by coupling local features and manifold ranking. At technical fronts, we exploit spatial pyramids based local structures to facilitate the efficient construction of feature descriptors. Meanwhile, we propose an improved manifold ranking method, wherein all the categories between arbitrary model pairs will be taken into account. Since the smooth and detail-preserving line drawings of 3D model are important for sketch-based 3D model retrieval, the Difference of Gaussians （DOG） method is employed to extract the line drawings over the projected depth images of 3D model, and Bezier Curve is then adopted to further optimize the extracted line drawing. On that basis, we develop a 3D model retrieval engine to verify our method. We have conducted extensive experiments over various public benchmarks, and have made comprehensive comparisons with some state-of-the-art 3D retrieval methods. All the evaluation results based on the widely-used indicators prove the superiority of our method in accuracy, reliability, robustness, and versatility.
基金supported in part by the Fundamental Research Funds for the Central Universities in China (No. 2100219066)the Key Fundamental Research Funds for the Central Universities in China (No. 0200219153)
文摘With the rapid development of Web3 D technologies, sketch-based model retrieval has become an increasingly important challenge, while the application of Virtual Reality and 3 D technologies has made shape retrieval of furniture over a web browser feasible. In this paper, we propose a learning framework for shape retrieval based on two Siamese VGG-16 Convolutional Neural Networks(CNNs), and a CNN-based hybrid learning algorithm to select the best view for a shape. In this algorithm, the AlexNet and VGG-16 CNN architectures are used to perform classification tasks and to extract features, respectively. In addition, a feature fusion method is used to measure the similarity relation of the output features from the two Siamese networks. The proposed framework can provide new alternatives for furniture retrieval in the Web3 D environment. The primary innovation is in the employment of deep learning methods to solve the challenge of obtaining the best view of 3 D furniture,and to address cross-domain feature learning problems. We conduct an experiment to verify the feasibility of the framework and the results show our approach to be superior in comparison to many mainstream state-of-the-art approaches.
基金supported by the National Natural Science Foundation of China (Project Nos. U1435220, 61232013)
文摘Large-scale dynamic relational data visualization has attracted considerable research attention recently. We introduce dynamic data visualization into the multimedia domain, and present an interactive and scalable system, Video Map, for exploring large-scale video content. A long video or movie has much content; the associations between the content are complicated. Video Map uses new visual representations to extract meaningful information from video content. Map-based visualization naturally and easily summarizes and reveals important features and events in video. Multi-scale descriptions are used to describe the layout and distribution of temporal information, spatial information, and associations between video content. Firstly, semantic associations are used in which map elements correspond to video contents. Secondly, video contents are visualized hierarchically from a large scale to a fine-detailed scale. Video Map uses a small set of sketch gestures to invoke analysis, and automatically completes charts by synthesizing visual representations from the map and binding them to the underlying data. Furthermore,Video Map allows users to use gestures to move and resize the view, as when using a map, facilitating interactive exploration. Our experimental evaluation of Video Map demonstrates how the system can assist in exploring video content as well as significantly reducing browsing time when trying to understand and find events of interest.
基金supported by the PDE-GIR project,which has received funding from the European Union Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No.778035by the project PID2021-127073OB-I00 of the MCIN/AEI/10.13039/501100011033/FEDER,EU+1 种基金by the Santander PGR Grantssupported by the Ningbo Major Special Projects of the“Science and Technology Innovation 2025”,grant No.2020Z007.
文摘Character models have enormous applications in industry.Efficient creation of detailed character models is an important topic.This paper proposes a new and easy-to-use technique to quickly create detailed character models from sketches.The proposed technique consists of two main components:primitive deformer and shape generators.With this technique,2D silhouette contours of a character model are drawn or extracted from an image or sketch.Then,proper geometric primitives are selected and aligned with the corresponding 2D silhouette contours.After that,a primitive deformer is used to create a base mesh and three shape generators are used to add 3D details to the base mesh.The primitive deformer and three shape generators are developed from ODE-driven deformations.The primitive deformer deforms the aligned geometric primitives to exactly match the 2D silhouette contours in one view plane and obtains a base mesh of a character model consisting of deformed primitives.The shape generators are used to add 3D details to the base mesh by creating local 3D models.The experimental results demonstrate that the new technique can quickly create detailed 3D character models from sketches with few manual operations.The new technique is physics-based and easy to learn and use.
文摘A novel and fast shape classification and regularization algorithm for on-line sketchy graphics recognition is proposed. We divide the on-line graphics recognition process into four stages: preprocessing,shape classification,shape fitting,and regularization. Attraction Force Model is employed to progressively combine the vertices on the input sketchy stroke and reduce the total number of vertices before the type of shape can be determined. After that ,the shape is fitted and gradually rectified to a regular one,thus the regularized shape fits the user intended one precisely.Experimental results show that this algorithm can yield good recognition precision(averagely above 90% )and fine regularization effect but with fast speed. Consequently,it is especially suitable to computational critical environment such as PDAs,which solely depends on a pen-based user interface.
