Proceedings of the 29th annual conference on Computer graphics and interactive techniques最新文献_第7页

Robust epsilon visibility 鲁棒的可见性

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566618

Florent Duguet, G. Drettakis

{"title":"Robust epsilon visibility","authors":"Florent Duguet, G. Drettakis","doi":"10.1145/566570.566618","DOIUrl":"https://doi.org/10.1145/566570.566618","url":null,"abstract":"Analytic visibility algorithms, for example methods which compute a subdivided mesh to represent shadows, are notoriously unrobust and hard to use in practice. We present a new method based on a generalized definition of extremal stabbing lines, which are the extremities of shadow boundaries. We treat scenes containing multiple edges or vertices in degenerate configurations, (e.g., collinear or coplanar). We introduce a robust ε method to determine whether each generalized extremal stabbing line is blocked, or is touched by these scene elements, and thus added to the line's generators. We develop robust blocker predicates for polygons which are smaller than ε. For larger ε values, small shadow features merge and eventually disappear. We can thus robustly connect generalized extremal stabbing lines in degenerate scenes to form shadow boundaries. We show that our approach is consistent, and that shadow boundary connectivity is preserved when features merge. We have implemented our algorithm, and show that we can robustly compute analytic shadow boundaries to the precision of our chosen ε threshold for non-trivial models, containing numerous degeneracies.","PeriodicalId":197746,"journal":{"name":"Proceedings of the 29th annual conference on Computer graphics and interactive techniques","volume":"301 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122800842","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}

引用次数: 60

Creating models of truss structures with optimization 创建桁架结构优化模型

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566580

Jeffrey Smith, J. Hodgins, I. Oppenheim, A. Witkin

引用次数: 72

Physiological measures of presence in stressful virtual environments 压力虚拟环境中存在的生理测量

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566630

M. Meehan, Brent Insko, M. Whitton, F. Brooks

{"title":"Physiological measures of presence in stressful virtual environments","authors":"M. Meehan, Brent Insko, M. Whitton, F. Brooks","doi":"10.1145/566570.566630","DOIUrl":"https://doi.org/10.1145/566570.566630","url":null,"abstract":"A common measure of the quality or effectiveness of a virtual environment (VE) is the mount of presence it evokes in users. Presence is often defined as the sense of being there in a VE. There has been much debate about the best way to measure presence, and presence researchers need, and have sought, a measure that is reliable, valid, sensitive, and objective.We hypothesized that to the degree that a VE seems real, it would evoke physiological responses similar to those evoked by the corresponding real environment, and that greater presence would evoke a greater response. To examine this, we conducted three experiments, the results of which support the use of physiological reaction as a reliable, valid, sensitive, and objective presence measure. The experiments compared participants' physiological reactions to a non-threatening virtual room and their reactions to a stressful virtual height situation. We found that change in heart rate satisfied our requirements for a measure of presence, change in skin conductance did to a lesser extent, and that change in skin temperature did not. Moreover, the results showed that inclusion of a passive haptic element in the VE significantly increased presence and that for presence evoked: 30FPS > 20FPS > 15FPS.","PeriodicalId":197746,"journal":{"name":"Proceedings of the 29th annual conference on Computer graphics and interactive techniques","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133743721","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}

引用次数: 644

Geometry images 几何图像

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566589

X. Gu, S. Gortler, Hugues Hoppe

引用次数: 878

Least squares conformal maps for automatic texture atlas generation 用于自动纹理图集生成的最小二乘保角贴图

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566590

B. Lévy, Sylvain Petitjean, N. Ray, J. Maillot

{"title":"Least squares conformal maps for automatic texture atlas generation","authors":"B. Lévy, Sylvain Petitjean, N. Ray, J. Maillot","doi":"10.1145/566570.566590","DOIUrl":"https://doi.org/10.1145/566570.566590","url":null,"abstract":"A Texture Atlas is an efficient color representation for 3D Paint Systems. The model to be textured is decomposed into charts homeomorphic to discs, each chart is parameterized, and the unfolded charts are packed in texture space. Existing texture atlas methods for triangulated surfaces suffer from several limitations, requiring them to generate a large number of small charts with simple borders. The discontinuities between the charts cause artifacts, and make it difficult to paint large areas with regular patterns.In this paper, our main contribution is a new quasi-conformal parameterization method, based on a least-squares approximation of the Cauchy-Riemann equations. The so-defined objective function minimizes angle deformations, and we prove the following properties: the minimum is unique, independent of a similarity in texture space, independent of the resolution of the mesh and cannot generate triangle flips. The function is numerically well behaved and can therefore be very efficiently minimized. Our approach is robust, and can parameterize large charts with complex borders.We also introduce segmentation methods to decompose the model into charts with natural shapes, and a new packing algorithm to gather them in texture space. We demonstrate our approach applied to paint both scanned and modeled data sets.","PeriodicalId":197746,"journal":{"name":"Proceedings of the 29th annual conference on Computer graphics and interactive techniques","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123315572","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}

引用次数: 1366

Real-time 3D model acquisition 实时三维模型获取

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566600

S. Rusinkiewicz, Olaf A. Hall-Holt, M. Levoy

引用次数: 765

Feature-based light field morphing 基于特征的光场变形

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566602

Zhunping Zhang, Lifeng Wang, B. Guo, H. Shum

{"title":"Feature-based light field morphing","authors":"Zhunping Zhang, Lifeng Wang, B. Guo, H. Shum","doi":"10.1145/566570.566602","DOIUrl":"https://doi.org/10.1145/566570.566602","url":null,"abstract":"We present a feature-based technique for morphing 3D objects represented by light fields. Our technique enables morphing of image-based objects whose geometry and surface properties are too difficult to model with traditional vision and graphics techniques. Light field morphing is not based on 3D reconstruction; instead it relies on ray correspondence, i.e., the correspondence between rays of the source and target light fields. We address two main issues in light field morphing: feature specification and visibility changes. For feature specification, we develop an intuitive and easy-to-use user interface (UI). The key to this UI is feature polygons, which are intuitively specified as 3D polygons and are used as a control mechanism for ray correspondence in the abstract 4D ray space. For handling visibility changes due to object shape changes, we introduce ray-space warping. Ray-space warping can fill arbitrarily large holes caused by object shape changes; these holes are usually too large to be properly handled by traditional image warping. Our method can deal with non-Lambertian surfaces, including specular surfaces (with dense light fields). We demonstrate that light field morphing is an effective and easy-to-use technqiue that can generate convincing 3D morphing effects.","PeriodicalId":197746,"journal":{"name":"Proceedings of the 29th annual conference on Computer graphics and interactive techniques","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126549808","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}

引用次数: 61

Jigsaw image mosaics 拼图图像马赛克

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566633

Junh-Nam Kim, F. Pellacini

引用次数: 218

Progressive lossless compression of arbitrary simplicial complexes 任意简单复合体的渐进无损压缩

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566591

Pierre-Marie Gandoin, O. Devillers

{"title":"Progressive lossless compression of arbitrary simplicial complexes","authors":"Pierre-Marie Gandoin, O. Devillers","doi":"10.1145/566570.566591","DOIUrl":"https://doi.org/10.1145/566570.566591","url":null,"abstract":"Efficient algorithms for compressing geometric data have been widely developed in the recent years, but they are mainly designed for closed polyhedral surfaces which are manifold or \"nearly manifold\". We propose here a progressive geometry compression scheme which can handle manifold models as well as \"triangle soups\" and 3D tetrahedral meshes. The method is lossless when the decompression is complete which is extremely important in some domains such as medical or finite element.While most existing methods enumerate the vertices of the mesh in an order depending on the connectivity, we use a kd-tree technique [Devillers and Gandoin 2000] which does not depend on the connectivity. Then we compute a compatible sequence of meshes which can be encoded using edge expansion [Hoppe et al. 1993] and vertex split [Popović and Hoppe 1997].The main contributions of this paper are: the idea of using the kd-tree encoding of the geometry to drive the construction of a sequence of meshes, an improved coding of the edge expansion and vertex split since the vertices to split are implicitly defined, a prediction scheme which reduces the code for simplices incident to the split vertex, and a new generalization of the edge expansion operation to tetrahedral meshes.","PeriodicalId":197746,"journal":{"name":"Proceedings of the 29th annual conference on Computer graphics and interactive techniques","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115166758","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}

引用次数: 209

A lighting reproduction approach to live-action compositing 实景合成的灯光再现方法

Proceedings of the 29th annual conference on Computer graphics and interactive techniques Pub Date : 2002-07-01 DOI: 10.1145/566570.566614

P. Debevec, Andreas Wenger, C. Tchou, A. Gardner, Jamie Waese, Tim Hawkins

引用次数: 172