Pub Date : 2000-10-03DOI: 10.1109/PCCGA.2000.883881
Jörg Haber, M. Stamminger, H. Seidel
Using well-adapted object hierarchies can support the rendering of large scenes in different ways. For instance, the quality of the lighting simulation may be improved, or the computational cost for rendering may be reduced. However the meaning of "well-adapted" depends heavily on the criterion due to which the hierarchy has been constructed. Different applications typically have different demands like low average intersection cost for a ray tracer or grouping objects with similar material properties or surface orientation for hierarchical radiosity. The authors propose an algorithm for the automatic creation of object hierarchies. The hierarchies are constructed by sequentially inserting all scene objects into the hierarchy created so far. By basing the insertion decision on a cost function defined by the user, the method can be guided to create hierarchies tailored to the desired application. The results can be improved significantly by running a global optimization on the completed hierarchy. During this optimization step, we perform a re-grouping of the objects in the hierarchy. Any ill-formed groups that were created during the initial algorithm are subject to being eliminated by our global optimization.
{"title":"Enhanced automatic creation of multi-purpose object hierarchies","authors":"Jörg Haber, M. Stamminger, H. Seidel","doi":"10.1109/PCCGA.2000.883881","DOIUrl":"https://doi.org/10.1109/PCCGA.2000.883881","url":null,"abstract":"Using well-adapted object hierarchies can support the rendering of large scenes in different ways. For instance, the quality of the lighting simulation may be improved, or the computational cost for rendering may be reduced. However the meaning of \"well-adapted\" depends heavily on the criterion due to which the hierarchy has been constructed. Different applications typically have different demands like low average intersection cost for a ray tracer or grouping objects with similar material properties or surface orientation for hierarchical radiosity. The authors propose an algorithm for the automatic creation of object hierarchies. The hierarchies are constructed by sequentially inserting all scene objects into the hierarchy created so far. By basing the insertion decision on a cost function defined by the user, the method can be guided to create hierarchies tailored to the desired application. The results can be improved significantly by running a global optimization on the completed hierarchy. During this optimization step, we perform a re-grouping of the objects in the hierarchy. Any ill-formed groups that were created during the initial algorithm are subject to being eliminated by our global optimization.","PeriodicalId":342067,"journal":{"name":"Proceedings the Eighth Pacific Conference on Computer Graphics and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133839167","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 : 2000-10-03DOI: 10.1109/PCCGA.2000.883972
X-Q. Dai, T. Furukawa, Shigeru Mitsui, Daiju Komai, M. Takatera, M. Hashimoto, Y. Shimizu
Even though a particle model based on the mechanical properties of woven cloth has been proposed by D.E. Breen et al. (1994), there are problems in describing the cloth behavior precisely and in reflecting the cloth dynamics. In this paper, we describe a precise relationship between the measured mechanical properties of cloth and the particle model. Moreover, a collision model describing the rotation as well as the movement of particles resulting from an impulse is integrated into the particle model. Some experiments involving two cloth materials are performed in order to validate the proposed cloth model.
{"title":"A particle model based on measured mechanical properties of woven cloth","authors":"X-Q. Dai, T. Furukawa, Shigeru Mitsui, Daiju Komai, M. Takatera, M. Hashimoto, Y. Shimizu","doi":"10.1109/PCCGA.2000.883972","DOIUrl":"https://doi.org/10.1109/PCCGA.2000.883972","url":null,"abstract":"Even though a particle model based on the mechanical properties of woven cloth has been proposed by D.E. Breen et al. (1994), there are problems in describing the cloth behavior precisely and in reflecting the cloth dynamics. In this paper, we describe a precise relationship between the measured mechanical properties of cloth and the particle model. Moreover, a collision model describing the rotation as well as the movement of particles resulting from an impulse is integrated into the particle model. Some experiments involving two cloth materials are performed in order to validate the proposed cloth model.","PeriodicalId":342067,"journal":{"name":"Proceedings the Eighth Pacific Conference on Computer Graphics and Applications","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132739232","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 : 2000-10-03DOI: 10.1109/PCCGA.2000.883971
S. Roth, Patrick Diezi, M. Gross
Introduces a new approach to finding ray-patch intersections with triangular Bernstein-Bezier patches of arbitrary degree. Unlike the approach of W.Sturzlinger (1998), which was based on a combination of hierarchical subdivision and a Newton-like iteration scheme, this work extends the concept of Bezier clipping to the triangular domain. The problem of reporting wrong intersections, which was inherent to the original Bezier clipping algorithm of T. Nishita et al. (1990), is investigated and opposed to the triangular case. It turns out that reporting wrong hits is very improbable, even close to impossible, in the triangular setup.
{"title":"Triangular Bezier clipping","authors":"S. Roth, Patrick Diezi, M. Gross","doi":"10.1109/PCCGA.2000.883971","DOIUrl":"https://doi.org/10.1109/PCCGA.2000.883971","url":null,"abstract":"Introduces a new approach to finding ray-patch intersections with triangular Bernstein-Bezier patches of arbitrary degree. Unlike the approach of W.Sturzlinger (1998), which was based on a combination of hierarchical subdivision and a Newton-like iteration scheme, this work extends the concept of Bezier clipping to the triangular domain. The problem of reporting wrong intersections, which was inherent to the original Bezier clipping algorithm of T. Nishita et al. (1990), is investigated and opposed to the triangular case. It turns out that reporting wrong hits is very improbable, even close to impossible, in the triangular setup.","PeriodicalId":342067,"journal":{"name":"Proceedings the Eighth Pacific Conference on Computer Graphics and Applications","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121405032","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 : 2000-05-03DOI: 10.1109/PCCGA.2000.883953
T. Endo, Makoto Sato, Y. Kajiki, T. Honda
We propose a 3-D video display technique that allows multiple viewers to observe 3-D images from a 360-degree horizontal arc without wearing 3-D glasses. This technique uses a cylindrical parallax barrier and a one-dimensional light source array. We have developed an experimental display using this technique and have demonstrated observation of 3-D images from a 360-degree horizontal arc without the use of 3-D glasses. Since this technique is based on the parallax panoramagram, the parallax number and resolution are limited by the diffraction at the parallax barrier. To overcome these limits, we improved the technique by revolving the parallax barrier. We have incorporated this new technique in our new experimental display. The display is capable of displaying cylindrical 3-D video images within a diameter of 100 mm and a height of 128 mm. Images are described with a resolution of 1254 pixels circularly and 128 pixels vertically and are refreshed at 30 Hz. Each pixel has a viewing angle of 60 degrees that is divided into 70 views, so the angular parallax interval of each pixel is less than 1 degree. In such a case, observers may barely perceive discrete parallax. The pixels are arranged on a cylindrical surface to allow the produced 3-D images to be observed from all directions.
{"title":"Cylindrical 3-D video display observable from all directions","authors":"T. Endo, Makoto Sato, Y. Kajiki, T. Honda","doi":"10.1109/PCCGA.2000.883953","DOIUrl":"https://doi.org/10.1109/PCCGA.2000.883953","url":null,"abstract":"We propose a 3-D video display technique that allows multiple viewers to observe 3-D images from a 360-degree horizontal arc without wearing 3-D glasses. This technique uses a cylindrical parallax barrier and a one-dimensional light source array. We have developed an experimental display using this technique and have demonstrated observation of 3-D images from a 360-degree horizontal arc without the use of 3-D glasses. Since this technique is based on the parallax panoramagram, the parallax number and resolution are limited by the diffraction at the parallax barrier. To overcome these limits, we improved the technique by revolving the parallax barrier. We have incorporated this new technique in our new experimental display. The display is capable of displaying cylindrical 3-D video images within a diameter of 100 mm and a height of 128 mm. Images are described with a resolution of 1254 pixels circularly and 128 pixels vertically and are refreshed at 30 Hz. Each pixel has a viewing angle of 60 degrees that is divided into 70 views, so the angular parallax interval of each pixel is less than 1 degree. In such a case, observers may barely perceive discrete parallax. The pixels are arranged on a cylindrical surface to allow the produced 3-D images to be observed from all directions.","PeriodicalId":342067,"journal":{"name":"Proceedings the Eighth Pacific Conference on Computer Graphics and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130499914","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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