Curvature tells much about details of surfaces and is studied widely by researchers in the computer graphics com- munity. In this paper, we first explain the mean-curvature view of Dirichlet energy of triangular surfa...Curvature tells much about details of surfaces and is studied widely by researchers in the computer graphics com- munity. In this paper, we first explain the mean-curvature view of Dirichlet energy of triangular surfaces and introduce a curvature representation of details, and then present surfaces editing applications based on their curvature representation. We apply our method to surfaces with complex boundaries and rich details. Results show the validity and robustness of our method and dem- onstrate curvature map can be a helpful surfaces detail representation.展开更多
Background Crossing-based target selection motion may attain less error rates and higher interactive speed in some cases.Most of the research in target selection fields are focused on the analysis of the interaction r...Background Crossing-based target selection motion may attain less error rates and higher interactive speed in some cases.Most of the research in target selection fields are focused on the analysis of the interaction results.Additionally,as trajectories play a much more important role in crossing-based target selection compared to the other interactive techniques,an ideal model for trajectories can help computer designers make predictions about interaction results during the process of target selection rather than at the end of the whole process.Methods In this paper,a trajectory prediction model for crossing based target selection tasks is proposed by taking the reference of a dynamic model theory.Results Simulation results demonstrate that our model performed well with regard to the prediction of trajectories,endpoints and hitting time for target-selection motion,and the average error of trajectories,endpoints and hitting time values were found to be 17.28%,2.73mm and 11.50%,respectively.展开更多
Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications...Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications. In this paper, we propose a parallel texture optimization algorithm to run on GPUs. In our algorithm, k-coherence search and principle component analysis （PCA） are used for hardware acceleration, and two acceleration techniques are further developed to speed up our GPU-based texture optimization. With a reasonable precomputation cost, the online synthesis speed of our algorithm is 4000＋ times faster than that of the original texture optimization algorithm and thus our algorithm is capable of interactive applications. The advantages of the new scheme are demonstrated by applying it to interactive editing of flow-guided synthesis.展开更多
This paper presents an interactive graphics processing unit （GPU）-based relighting system in which local lighting condition, surface materials and viewing direction can all be changed on the fly. To support these ch...This paper presents an interactive graphics processing unit （GPU）-based relighting system in which local lighting condition, surface materials and viewing direction can all be changed on the fly. To support these changes, we simulate the lighting transportation process at run time, which is normally impractical for interactive use due to its huge computational burden. We greatly alleviate this burden by a hierarchical structure named a transportation tree that clusters similar emitting samples together within a perceptually acceptable error bound. Furthermore, by exploiting the coherence in time as well as in space, we incrementally adjust the clusters rather than computing them from scratch in each frame. With a pre-computed visibility map, we are able to efficiently estimate the indirect illumination in parallel on graphics hardware, by simply summing up the radiance shoots from cluster representatives, plus a small number of operations of merging and splitting on clusters. With relighting based on the time-varying clusters, interactive update of global illumination effects with multi-bounced indirect lighting is demonstrated in applications to material animation and scene decoration.展开更多
Sequential point trees provide the state-of-the-art technique for rendering point models, by re-arranging hierarchical points sequentially according to geometric errors running on GPU for fast rendering. This paper pr...Sequential point trees provide the state-of-the-art technique for rendering point models, by re-arranging hierarchical points sequentially according to geometric errors running on GPU for fast rendering. This paper presents a view dependent method to augment sequential point trees by embedding the hierarchical tree structures in the sequential list of hierarchical points. By the method, two kinds of indices are constructed to facilitate the points rendering in an order mostly from near to far and from coarse to fine. As a result, invisible points can be culled view-dependently in high efficiency for hardware acceleration, and at the same time, the advantage of sequential point trees could be still fully taken. Therefore, the new method can run much faster than the conventional sequential point trees, and the acceleration can be highly promoted particularly when the objects possess complex occlusion relationship and viewed closely because invisible points would be in a high percentage of the points at finer levels.展开更多
基金Project supported by the National Basic Research Program (973) of China (No. 2002CB312102), and the Research Grant of University of Macao, China
文摘Curvature tells much about details of surfaces and is studied widely by researchers in the computer graphics com- munity. In this paper, we first explain the mean-curvature view of Dirichlet energy of triangular surfaces and introduce a curvature representation of details, and then present surfaces editing applications based on their curvature representation. We apply our method to surfaces with complex boundaries and rich details. Results show the validity and robustness of our method and dem- onstrate curvature map can be a helpful surfaces detail representation.
基金National Key R&D Program of China(2016YFB1001405)the National Natural Science Foundation of China(61802379)Key Research Program of Frontier Sciences,CAS(QYZDY-SSW-JSC041).
文摘Background Crossing-based target selection motion may attain less error rates and higher interactive speed in some cases.Most of the research in target selection fields are focused on the analysis of the interaction results.Additionally,as trajectories play a much more important role in crossing-based target selection compared to the other interactive techniques,an ideal model for trajectories can help computer designers make predictions about interaction results during the process of target selection rather than at the end of the whole process.Methods In this paper,a trajectory prediction model for crossing based target selection tasks is proposed by taking the reference of a dynamic model theory.Results Simulation results demonstrate that our model performed well with regard to the prediction of trajectories,endpoints and hitting time for target-selection motion,and the average error of trajectories,endpoints and hitting time values were found to be 17.28%,2.73mm and 11.50%,respectively.
基金The IOS authors are partially supported by the National High Technology Development 863 Program of China under Grant No.2006AA01Z306the National Grand Fundamental Research 973 Program of China under Grant No.2002CB312102.
文摘Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications. In this paper, we propose a parallel texture optimization algorithm to run on GPUs. In our algorithm, k-coherence search and principle component analysis （PCA） are used for hardware acceleration, and two acceleration techniques are further developed to speed up our GPU-based texture optimization. With a reasonable precomputation cost, the online synthesis speed of our algorithm is 4000＋ times faster than that of the original texture optimization algorithm and thus our algorithm is capable of interactive applications. The advantages of the new scheme are demonstrated by applying it to interactive editing of flow-guided synthesis.
基金Supported by the National Basic Research Program of China (Grant No. 2009CB320802)the National Natural Science Foundation of China(Grant No. 60833007)+1 种基金the National High-Tech Research & Development Progran of China (Grant No. 2008AA01Z301)the ResearchGrant of the University of Macao
文摘This paper presents an interactive graphics processing unit （GPU）-based relighting system in which local lighting condition, surface materials and viewing direction can all be changed on the fly. To support these changes, we simulate the lighting transportation process at run time, which is normally impractical for interactive use due to its huge computational burden. We greatly alleviate this burden by a hierarchical structure named a transportation tree that clusters similar emitting samples together within a perceptually acceptable error bound. Furthermore, by exploiting the coherence in time as well as in space, we incrementally adjust the clusters rather than computing them from scratch in each frame. With a pre-computed visibility map, we are able to efficiently estimate the indirect illumination in parallel on graphics hardware, by simply summing up the radiance shoots from cluster representatives, plus a small number of operations of merging and splitting on clusters. With relighting based on the time-varying clusters, interactive update of global illumination effects with multi-bounced indirect lighting is demonstrated in applications to material animation and scene decoration.
基金A preliminary version of this paper appeared in Proc. Pacific Graphics 2005, Macao. The work is supported by the National Basic Research 973 Program of China （Grant No. 2002CB312102）, the National Natural Science Foundation of China （Grant Nos. 60373051, 60473105） and the Research Grant of the University of Macao.
文摘Sequential point trees provide the state-of-the-art technique for rendering point models, by re-arranging hierarchical points sequentially according to geometric errors running on GPU for fast rendering. This paper presents a view dependent method to augment sequential point trees by embedding the hierarchical tree structures in the sequential list of hierarchical points. By the method, two kinds of indices are constructed to facilitate the points rendering in an order mostly from near to far and from coarse to fine. As a result, invisible points can be culled view-dependently in high efficiency for hardware acceleration, and at the same time, the advantage of sequential point trees could be still fully taken. Therefore, the new method can run much faster than the conventional sequential point trees, and the acceleration can be highly promoted particularly when the objects possess complex occlusion relationship and viewed closely because invisible points would be in a high percentage of the points at finer levels.
