Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.731992
T. Kunii
Current graphics models suffer from inconsistencies in many ways. Neither homotopical nor topological properties have been inherited in the shapes of graphical objects in particular, and usually continuity and singularity properties are not inherited either. For example, since the most of the shape modeling in computer graphics has polygonalization as the underlying display structures and data structures, the topological properties as well as the shape smoothness properties and singularities are almost always lost, which makes them unrecoverable. We present initial research on shape modeling for computer graphics to remedy this situation, based on a homotopical framework and cellular spatial structures.
{"title":"Graphics with shape property inheritance","authors":"T. Kunii","doi":"10.1109/PCCGA.1998.731992","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.731992","url":null,"abstract":"Current graphics models suffer from inconsistencies in many ways. Neither homotopical nor topological properties have been inherited in the shapes of graphical objects in particular, and usually continuity and singularity properties are not inherited either. For example, since the most of the shape modeling in computer graphics has polygonalization as the underlying display structures and data structures, the topological properties as well as the shape smoothness properties and singularities are almost always lost, which makes them unrecoverable. We present initial research on shape modeling for computer graphics to remedy this situation, based on a homotopical framework and cellular spatial structures.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116134106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.732134
T. Moritsu, M. Kato
Two new techniques for view morphing are presented. The first technique is a disparity mapping technique which accurately maps the edges of input images on each other. By using this technique, one can reduce the blurring of synthesized images. The second technique is a data transformation technique which transforms morphing data into data which can be rendered on ordinary 3D graphic accelerators. By using this transformation, one achieve interactive morphing animations.
{"title":"Disparity mapping technique and fast rendering technique for view morphing","authors":"T. Moritsu, M. Kato","doi":"10.1109/PCCGA.1998.732134","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.732134","url":null,"abstract":"Two new techniques for view morphing are presented. The first technique is a disparity mapping technique which accurately maps the edges of input images on each other. By using this technique, one can reduce the blurring of synthesized images. The second technique is a data transformation technique which transforms morphing data into data which can be rendered on ordinary 3D graphic accelerators. By using this transformation, one achieve interactive morphing animations.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122631858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.732103
Golam Ashraf, Kok Cheong Wong
To enhance the realism of computer animation sequences, the interaction between autonomous creatures and their environment needs to be modeled. Two such commonly occurring phenomena, dust and water splashing on impact, are presented. These pseudo dynamic models, based on particle system concepts, are designed for hoppers with approximately elliptical bases. The proposed models can be extended for use with multi-legged creatures. The dust model is parameterized by creature dimensions, soil particle dimensions and wind direction. The water splashing model is parameterized by creature dimensions and water film thickness. Explicit control of behavioral parameters of both models is also provided to allow application specific usage.
{"title":"Dust and water splashing models for hopping figures","authors":"Golam Ashraf, Kok Cheong Wong","doi":"10.1109/PCCGA.1998.732103","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.732103","url":null,"abstract":"To enhance the realism of computer animation sequences, the interaction between autonomous creatures and their environment needs to be modeled. Two such commonly occurring phenomena, dust and water splashing on impact, are presented. These pseudo dynamic models, based on particle system concepts, are designed for hoppers with approximately elliptical bases. The proposed models can be extended for use with multi-legged creatures. The dust model is parameterized by creature dimensions, soil particle dimensions and wind direction. The water splashing model is parameterized by creature dimensions and water film thickness. Explicit control of behavioral parameters of both models is also provided to allow application specific usage.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121721889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.732132
R. Jegathese, E. Prakash
A new volume deformation technique using FEM and voxel-texture (voxture) maps has been developed. In contrast to the traditional deformation techniques, the new algorithm is aimed at volume transformations, deformations and volume metamorphosis.
{"title":"A new approach for goal-oriented deformation of voxel models","authors":"R. Jegathese, E. Prakash","doi":"10.1109/PCCGA.1998.732132","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.732132","url":null,"abstract":"A new volume deformation technique using FEM and voxel-texture (voxture) maps has been developed. In contrast to the traditional deformation techniques, the new algorithm is aimed at volume transformations, deformations and volume metamorphosis.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125182730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.732100
Liwei Zhao, N. Badler
Gesture and speech are two very important behaviors for virtual humans. They are not isolated from each other but generally employed simultaneously in the service of the same intention. An underlying PaT-Net parallel finite state machine may be used to coordinate them both. Gesture selection is not arbitrary. Typical movements correlated with specific textual elements are used to select and produce gesticulation online. This enhances the expressiveness of speaking virtual humans.
{"title":"Gesticulation behaviors for virtual humans","authors":"Liwei Zhao, N. Badler","doi":"10.1109/PCCGA.1998.732100","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.732100","url":null,"abstract":"Gesture and speech are two very important behaviors for virtual humans. They are not isolated from each other but generally employed simultaneously in the service of the same intention. An underlying PaT-Net parallel finite state machine may be used to coordinate them both. Gesture selection is not arbitrary. Typical movements correlated with specific textual elements are used to select and produce gesticulation online. This enhances the expressiveness of speaking virtual humans.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124709598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.731993
Weiqiang Zhang, Zesheng Tang, Jie Li
A fast algorithm for large scale scattered data approximation is described. The algorithm exploits a coarse-to-fine hierarchical control lattice to fit the scattered data. In this algorithm, the refinement process is only located in the regions where the error between the scattered data and the resulting surface is greater than a specified tolerance. A recursive algorithm is used to find these regions. In order to ensure the C/sup 2/-continuity of the resulting surfaces, we introduce an additional method to get the boundary control points around the subcontrol lattice. Experimental results are included to show that this method can approximate large scale scattered data sets quickly.
{"title":"Adaptive hierarchical b-spline surface approximation of large-scale scattered data","authors":"Weiqiang Zhang, Zesheng Tang, Jie Li","doi":"10.1109/PCCGA.1998.731993","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.731993","url":null,"abstract":"A fast algorithm for large scale scattered data approximation is described. The algorithm exploits a coarse-to-fine hierarchical control lattice to fit the scattered data. In this algorithm, the refinement process is only located in the regions where the error between the scattered data and the resulting surface is greater than a specified tolerance. A recursive algorithm is used to find these regions. In order to ensure the C/sup 2/-continuity of the resulting surfaces, we introduce an additional method to get the boundary control points around the subcontrol lattice. Experimental results are included to show that this method can approximate large scale scattered data sets quickly.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130578590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.732031
Moon-Ryul Jung, Hyunwoo Park, Doowon Paik
When volume data is visualized by the ray casting method, the color value of each pixel in the image is obtained by composing the color contributions of the sample points that lie on the ray cast from the pixel point. In most ray tracing methods, including M. Levoy's (1988; 1990) classical method, the color composition is formulated as a summation of the color contributions of the discrete sample points. However the more precise color composition is formulated as differential equations over the color contributions of the continuous sample points. The discrete formulation is used, because analytical solutions to the continuous formulation are hard to find. However we have discovered a semi-analytical solution to the continuous formulation of a typical ray tracing of volume data. We have applied both Levoy's method and ours to the same set of data, and compared the visual quality of both results. The comparison shows that our method produces a more fine grained visualization of volume data.
{"title":"An analytical ray casting of volume data","authors":"Moon-Ryul Jung, Hyunwoo Park, Doowon Paik","doi":"10.1109/PCCGA.1998.732031","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.732031","url":null,"abstract":"When volume data is visualized by the ray casting method, the color value of each pixel in the image is obtained by composing the color contributions of the sample points that lie on the ray cast from the pixel point. In most ray tracing methods, including M. Levoy's (1988; 1990) classical method, the color composition is formulated as a summation of the color contributions of the discrete sample points. However the more precise color composition is formulated as differential equations over the color contributions of the continuous sample points. The discrete formulation is used, because analytical solutions to the continuous formulation are hard to find. However we have discovered a semi-analytical solution to the continuous formulation of a typical ray tracing of volume data. We have applied both Levoy's method and ours to the same set of data, and compared the visual quality of both results. The comparison shows that our method produces a more fine grained visualization of volume data.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128117786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.732101
Young-Min Kang, Hwan-Gue Cho, Ee-Taek Lee
The most important goal of character animation is to efficiently control the motions of a character. Until now, many techniques have been proposed for human gait animation, and some techniques have been created to control the emotions in gaits such as "tired walking" and "brisk walking" by using parameter interpolation or motion data mapping. Since it is very difficult to automate the control over the emotion of a motion, the emotions of a character model have been generated by creative animators. The paper proposes a human running model based on a one-leg-planar hopper with a self-balancing mechanism. The proposed technique exploits genetic programming to find an optimal movement. We extend the energy minimization technique to generate various motions in accordance with emotional specifications, for instance, "brisk running".
{"title":"An efficient control over human running animation with extension of planar hopper model","authors":"Young-Min Kang, Hwan-Gue Cho, Ee-Taek Lee","doi":"10.1109/PCCGA.1998.732101","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.732101","url":null,"abstract":"The most important goal of character animation is to efficiently control the motions of a character. Until now, many techniques have been proposed for human gait animation, and some techniques have been created to control the emotions in gaits such as \"tired walking\" and \"brisk walking\" by using parameter interpolation or motion data mapping. Since it is very difficult to automate the control over the emotion of a motion, the emotions of a character model have been generated by creative animators. The paper proposes a human running model based on a one-leg-planar hopper with a self-balancing mechanism. The proposed technique exploits genetic programming to find an optimal movement. We extend the energy minimization technique to generate various motions in accordance with emotional specifications, for instance, \"brisk running\".","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117218073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.732114
Moon-Ryul Jung, Doowon Paik, Donghyun Kim
The paper describes a camera control interface for the exploration of 3D virtual space implemented by using a 2D input device, a joystick. The interface uses a helicopter maneuver metaphor: the viewpoint of the virtual camera is controlled as if the user sits in a helicopter and controls its motion. To control the helicopter by a 2D input device, the 6D space of the helicopter motion is decomposed into six 2D subspaces. The 2D subspaces are visualized by means of the helicopter model and some auxiliary means, e.g. plane meshes and circles, to suggest the kind of motion allowed in each subspace. The visualized subspaces are used as camera control widgets controlled by the 2D input device. The six widgets are arranged so that the transition from one widget to another may be performed by one movement of the input device. This interface provides a simple and consistent kinesthetic correspondence between the movement of the joystick and the motion of the helicopter i.e. the virtual camera. We have conducted an evaluation of our camera control interface through a questionnaire study. Though it indicates that users of different levels find our interface easier to use compared to other interfaces, we need more rigorous evaluation studies to prove it. The main claim of the paper is that the proposed interface has a cleaner and more logical design obtained by strictly following a good design principle, i.e. systematic decomposition and intuitive visual clues.
{"title":"A camera control interface based on the visualization of subspaces of the 6D motion space of the camera","authors":"Moon-Ryul Jung, Doowon Paik, Donghyun Kim","doi":"10.1109/PCCGA.1998.732114","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.732114","url":null,"abstract":"The paper describes a camera control interface for the exploration of 3D virtual space implemented by using a 2D input device, a joystick. The interface uses a helicopter maneuver metaphor: the viewpoint of the virtual camera is controlled as if the user sits in a helicopter and controls its motion. To control the helicopter by a 2D input device, the 6D space of the helicopter motion is decomposed into six 2D subspaces. The 2D subspaces are visualized by means of the helicopter model and some auxiliary means, e.g. plane meshes and circles, to suggest the kind of motion allowed in each subspace. The visualized subspaces are used as camera control widgets controlled by the 2D input device. The six widgets are arranged so that the transition from one widget to another may be performed by one movement of the input device. This interface provides a simple and consistent kinesthetic correspondence between the movement of the joystick and the motion of the helicopter i.e. the virtual camera. We have conducted an evaluation of our camera control interface through a questionnaire study. Though it indicates that users of different levels find our interface easier to use compared to other interfaces, we need more rigorous evaluation studies to prove it. The main claim of the paper is that the proposed interface has a cleaner and more logical design obtained by strictly following a good design principle, i.e. systematic decomposition and intuitive visual clues.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"155 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132636757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-10-26DOI: 10.1109/PCCGA.1998.731998
Y. Dobashi, T. Nishita, H. Yamashita, T. Okita
The paper proposes an image based modeling of clouds where realistic clouds are created from satellite images using metaballs. The intention of the paper is for applications to space flight simulators, the visualization of the weather information, and the simulation of surveys of the Earth. In the proposed method, the density distribution inside the clouds is defined by a set of metaballs. Parameters of metaballs, such as center positions, radii, and density values, are automatically determined so that a synthesized image of clouds modeled by using metaballs is similar to the original satellite image. We also propose an animation method for clouds generated by a sequence of satellite images taken at some interval. The usefulness of the proposed method is demonstrated by several examples of clouds generated from satellite images of typhoons passing through Japan.
{"title":"Modeling of clouds from satellite images using metaballs","authors":"Y. Dobashi, T. Nishita, H. Yamashita, T. Okita","doi":"10.1109/PCCGA.1998.731998","DOIUrl":"https://doi.org/10.1109/PCCGA.1998.731998","url":null,"abstract":"The paper proposes an image based modeling of clouds where realistic clouds are created from satellite images using metaballs. The intention of the paper is for applications to space flight simulators, the visualization of the weather information, and the simulation of surveys of the Earth. In the proposed method, the density distribution inside the clouds is defined by a set of metaballs. Parameters of metaballs, such as center positions, radii, and density values, are automatically determined so that a synthesized image of clouds modeled by using metaballs is similar to the original satellite image. We also propose an animation method for clouds generated by a sequence of satellite images taken at some interval. The usefulness of the proposed method is demonstrated by several examples of clouds generated from satellite images of typhoons passing through Japan.","PeriodicalId":164343,"journal":{"name":"Proceedings Pacific Graphics '98. Sixth Pacific Conference on Computer Graphics and Applications (Cat. No.98EX208)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132131117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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