PG2015short

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https://diglib.eg.org/handle/10.2312/13267

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Browsing PG2015short by Subject "I.3.7 [Computer Graphics]"

Now showing 1 - 4 of 4
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    Accelerating Graph-based Path Planning Through Waypoint Clustering
    (The Eurographics Association, 2015) Wardhana, Nicholas Mario; Johan, Henry; Seah, Hock-Soon; Stam, Jos and Mitra, Niloy J. and Xu, Kun
    Modern Computer Graphics applications commonly feature very large virtual environments and diverse characters which perform different kinds of motions. To accelerate path planning in such scenario, we propose subregion graph data structure. It consists of subregions, which are clusters of locally connected waypoints inside a region, as well as their connectivities. We also present a fast algorithm to automatically generate subregion graph from enhanced waypoint graph map representation, which also supports various motion types and can be created from large virtual environments. Nevertheless, subregion graph can also be generated from any graph-based map representation. Our experiments showed that subregion graph is very compact relative to the input waypoint graph. By firstly planning subregion path, and then limiting waypoint-level planning to the subregion path, up to 8 times average speedup can be achieved, while average length ratios are maintained at as low as 102.5%.
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    Adaptive Hierarchical Shape Matching
    (The Eurographics Association, 2015) Tian, Yuan; Yang, Yin; Guo, Xiaohu; Prabhakaran, Balakrishnan; Stam, Jos and Mitra, Niloy J. and Xu, Kun
    In this paper, we present an adaptive hierarchical method allowing users to interact with geometrically complex 3D deformable objects based on an extended shape matching approach. Our method extends the existing multiresolution shape matching methods with improved energy convergence rate. This is achieved by using adaptive integration strategies to avoid insignificant shape matching iterations during the simulation. As demonstrated in our experimental results, the proposed method provides an efficient yet stable deformable simulation of complex models in real-time.
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    Complex Modulation Computer-Generated Hologram with Occlusion Effect by a Fast Hybrid Point-source/Wave-field Approach
    (The Eurographics Association, 2015) Gilles, Antonin; Gioia, Patrick; Cozot, Rémi; Morin, Luce; Stam, Jos and Mitra, Niloy J. and Xu, Kun
    We propose a fast Computer-Generated Hologram (CGH) computation method with occlusion effect based on a hybrid point-source/wave-field approach. Whereas previously proposed methods tried to reduce the computational complexity of the point-source or the wave-field approaches independently, the proposed method uses the two approaches together and therefore takes advantages from both of them. Our algorithm consists of three steps. First, the 3D scene is sliced into several depth layers parallel to the hologram plane. Then, light scattered by the scene is propagated and shielded from one layer to another, starting from the farthest layer. For each layer, light propagation and light shielding are performed using either a point-source or a wave-field approach according to a threshold criterion on the number of points within the layer. Finally, we compute light propagation from the nearest layer to the hologram plane in order to obtain the final CGH. Experimental results reveal that this combination of approaches does not produce any visible artifact and outperforms both the point-source and wavefield approaches.
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    Modal Space Subdivision for Physically-plausible 4D Shape Sequence Completion from Sparse Samples
    (The Eurographics Association, 2015) Xia, Qing; Li, Shuai; Qin, Hong; Hao, Aimin; Stam, Jos and Mitra, Niloy J. and Xu, Kun
    Subdivision techniques are powerful and ubiquitous in generating smooth surfaces from coarse 3D polygonal models, yet space-time subdivision remains unexplored when the goal is to produce dense physically-realistic shape sequence with smooth transition from a set of sparse 3D model samples. In this paper, we considers a completely data-driven strategy and proposes a novel modal space subdivision scheme to facilitate the rapid generation of physically-plausible "in-between" shapes from sparse model samples. The key idea of our approach is to abstract any shape as a point in modal space, represent its potential deformation with shape modes, and iteratively seek all the intermediate shapes between two consecutive models in the modal space via recursive subdivision. Meanwhile, to guarantee deformation details, we further interpolate the shape in the local regions after global modal-space subdivision. Comprehensive experiments on various model inputs have demonstrated the power, versatility, high performance, and potential of our modal space subdivision scheme.