Browsing by Author "Guo, Jianwei"

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    Feature Curve Network Extraction via Quadric Surface Fitting
    (The Eurographics Association, 2019) Zhengda, Lu; Guo, Jianwei; Xiao, Jun; Wang, Ying; Zhang, Xiaopeng; Yan, Dong-Ming; Lee, Jehee and Theobalt, Christian and Wetzstein, Gordon
    Feature curves on 3D shapes provide a high dimensional representation of the geometry and reveal their underlying structure. In this paper, we present an automatic approach for extracting complete feature curve networks from 3D models, as well as generating a high-quality patch layout. Starting from an initial collection of noisy and fragmented feature curves, we first filter non-salient or noisy feature curves by utilizing a quadric surface fitting technique. We then handle the curve intersections and curve missing by conducting a feature extension step to form a closed feature curve network. Finally, we generate a patch layout to reveal a highly structured representation of the input surfaces. Experimental results demonstrate that our algorithm is robust for extracting complete feature curve networks from complex input meshes and achieves superior quality patch layouts compared with the state-of-the-art approaches.
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    Instant Stippling on 3D Scenes
    (The Eurographics Association and John Wiley & Sons Ltd., 2018) Ma, Lei; Guo, Jianwei; Yan, Dong-Ming; Sun, Hanqiu; Chen, Yanyun; Fu, Hongbo and Ghosh, Abhijeet and Kopf, Johannes
    In this paper, we present a novel real-time approach to generate high-quality stippling on 3D scenes. The proposed method is built on a precomputed 2D sample sequence called incremental Voronoi set with blue-noise properties. A rejection sampling scheme is then applied to achieve tone reproduction, by thresholding the sample indices proportional to the inverse target tonal value to produce a suitable stipple density. Our approach is suitable for stippling large-scale or even dynamic scenes because the thresholding of individual stipples is trivially parallelizable. In addition, the static nature of the underlying sequence benefits the frame-to-frame coherence of the stippling. Finally, we propose an extension that supports stipples of varying sizes and tonal values, leading to smoother spatial and temporal transitions. Experimental results reveal that the temporal coherence and real-time performance of our approach are superior to those of previous approaches.
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    Tree Growth Modelling Constrained by Growth Equations
    (© 2018 The Eurographics Association and John Wiley & Sons Ltd., 2018) Yi, Lei; Li, Hongjun; Guo, Jianwei; Deussen, Oliver; Zhang, Xiaopeng; Chen, Min and Benes, Bedrich
    Modelling and simulation of tree growth that is faithful to the living environment and numerically consistent to botanic knowledge are important topics for realistic modelling in computer graphics. The realism factors concerned include the effects of complex environment on tree growth and the reliability of the simulation in botanical research, such as horticulture and agriculture. This paper proposes a new approach, namely, integrated growth modelling, to model virtual trees and simulate their growth by enforcing constraints of environmental resources and tree morphological properties. Morphological properties are integrated into a growth equation with different parameters specified in the simulation, including its sensitivity to light, allocation and usage of received resources and effects on its environment. The growth equation guarantees that the simulation procedure numerically matches the natural growth phenomenon of trees. With this technique, the growth procedures of diverse and realistic trees can also be modelled in different environments, such as resource competition among multiple trees.Modelling and simulation of tree growth that is faithful to the living environment and numerically consistent to botanic knowledge are important topics for realistic modelling in computer graphics. The realism factors concerned include the effects of complex environment on tree growth and the reliability of the simulation in botanical research, such as horticulture and agriculture. This paper proposes a new approach, namely, integrated growth modelling, to model virtual trees and simulate their growth by enforcing constraints of environmental resources and tree morphological properties. Morphological properties are integrated into a growth equation with different parameters specified in the simulation, including its sensitivity to light, allocation and usage of received resources and effects on its environment. The growth equation guarantees that the simulation procedure numerically matches the natural growth phenomenon of trees.