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Variational constraints in 3D

C. Durand, C.M. Hoffmann
1999 Proceedings Shape Modeling International '99. International Conference on Shape Modeling and Applications  
We discuss how to solve variational constraint problems involving points, lines and planes. We concentrate on small problems that must be solved simultaneously.  ...  In the case of planar constraint problems, there are fast variational solvers based on restrictions that do not confine applications in CAD.  ...  Furthermore, variations of the problem, in which some of the points are replaced with planes and some of the distance constraints with angle constraints, are also solvable with this generic approach.  ... 
doi:10.1109/sma.1999.749328 dblp:conf/smi/DurandH99 fatcat:ri5ge2wg6bbmffyvaiqzpx47xa

Surface Reconstruction from Sparse & Arbitrarily Oriented Contours in Freehand 3D Ultrasound

Shuangcheng Deng, Yunhua Li, Lipei Jiang, Yingyu Cao, Junwen Zhang
2013 Journal of Computers  
in 3D.  ...  In the new method, we first constructed on-and off-surface constraints from the segmented contours of all recorded B-scans and then used a variational interpolation technique to get a single implicit function  ...  CONCLUSION We present a new approach for the surface reconstruction of sparse and mutually-intersected contours in freehand 3D ultrasound imaging based on variational interpolation.  ... 
doi:10.4304/jcp.8.5.127-1285 fatcat:h4c6jk7zgjfuhbgclpia574xxe

Shape transformation using variational implicit functions

Greg Turk, James F. O'Brien
2005 ACM SIGGRAPH 2005 Courses on - SIGGRAPH '05  
We then invoke a variational interpolation technique (the 3D generalization of thin-plate interpolation), and this yields a single implicit function in 3D.  ...  For the case of 2D shapes, we place all of our data constraints within two planes, one for each shape. These planes are placed parallel to one another in 3D.  ...  Acknowledgements This work owes a good deal to Andrew Glassner for getting us interested in the shape transformation problem.  ... 
doi:10.1145/1198555.1198639 dblp:conf/siggraph/TurkO05 fatcat:srmpyuwghjbbjfw36dnxh2lgvq

Shape transformation using variational implicit functions

Greg Turk, James F. O'Brien
1999 Proceedings of the 26th annual conference on Computer graphics and interactive techniques - SIGGRAPH '99  
We then invoke a variational interpolation technique (the 3D generalization of thin-plate interpolation), and this yields a single implicit function in 3D.  ...  For the case of 2D shapes, we place all of our data constraints within two planes, one for each shape. These planes are placed parallel to one another in 3D.  ...  Acknowledgements This work owes a good deal to Andrew Glassner for getting us interested in the shape transformation problem.  ... 
doi:10.1145/311535.311580 dblp:conf/siggraph/TurkO99 fatcat:dtxkpuvqmbhepaleohn2cmzxfu

3D Stress intensity factor and T-stresses (T11 and T33) formulations for a Compact Tension specimen

S. K. Kudari, K. G. Kodancha
2016 Frattura ed Integrità Strutturale  
These formulations help to estimate magnitudes of 3D K I and T 11 and T 33 which are helpful to quantify in-plane and out-of-plane constraint effect of the crack tip.  ...  Formulations to estimate 3D K I , T 11 and T 33 stresses are proposed based on extensive 3D Finite element analyses.  ...  The proposed analytical formulations can be used to estimate the maximum 3D K I , T 11 and T 33 for the CT specimen, which are helpful in quantifying in-plane and out-ofplane constraint issues in fracture  ... 
doi:10.3221/igf-esis.39.21 fatcat:txlf5fyhzrbnpntez22ahgoc6u

Acquiring 3D models of non-rigid moving objects from time and viewpoint varying image sequences: a step toward left ventricle recovery

Y. Sato, M. Moriyama, M. Hanayama, H. Naito, S. Tamura
1997 IEEE Transactions on Pattern Analysis and Machine Intelligence  
Index Terms-3D shape recovery, non-rigid object, left ventricle, angiographic image analysis, multiple view integration, time-viewpoint space.  ...  This paper describes a method for the accurate recovery of time-varying 3D shapes with known cycle from images with different viewpoints as well as times, aiming at the recovery of the left ventricular  ...  ACKNOWLEDGMENTS The authors would like to thank Hiroki Kaihori and Takeshi Sakamoto for their assistance in the experiments.  ... 
doi:10.1109/34.584103 fatcat:ek6suodn6nhzpawqw4qdiwth7i

System-level process variability analysis and mitigation for 3D MPSoCs

S. Garg, D. Marculescu
2009 2009 Design, Automation & Test in Europe Conference & Exhibition  
system performance constraints.  ...  First, we develop analytical system-level models of the impact of process variations on the performance of FS 3D designs.  ...  be the RV corresponding to the variation in delay of critical path j in layer i due to WID variations.  ... 
doi:10.1109/date.2009.5090739 dblp:conf/date/GargM09 fatcat:dfkuvd76enc2vmsl5wx7si7pt4

Improved 3D assisted pose-invariant face recognition

Liting Wang, Liu Ding, Xiaoqing Ding, Chi Fang
2009 2009 IEEE International Conference on Acoustics, Speech and Signal Processing  
In this paper, we locate 88 sparse points from the 2D face sample by automatic face fitting and use their correspondence in the 3D face as shape constraint.  ...  For each sample, a 3D face is constructed by using 3D Morphable Model (3DMM).  ...  They estimate 3D shape from 2D sparse points only, but in this paper, we estimate 3D shape from both image intensity and shape constraint by modifying the energy function. Figure. 1.  ... 
doi:10.1109/icassp.2009.4959727 dblp:conf/icassp/WangDDF09 fatcat:r5il2cbejbht7gst2uz7tiigx4

Three Dimensional Manufacturing Tolerance Design Using Convex Sets

Jin Zhang, Lihong Qiao
2013 Procedia CIRP  
In this paper, 3D process dimension and manufacturing tolerance design issue is studied. A 3D tolerance zone calculation method is developed.  ...  High demand of wide use of three-dimensional operation models in process planning has resulted in an urgent exploration of new approaches to 3D manufacturing process design.  ...  Meanwhile, the variation ranges and constraints of the 3D tolerance torsor parameters are identified by the POAM mentioned above.  ... 
doi:10.1016/j.procir.2013.08.039 fatcat:opa4jj2syzfbdar5xdkmunamne

Variation of stress intensity factor and elastic T-stress along the crack-front in finite thickness plates

K. G. Kodancha, S. K. Kudari
2009 Frattura ed Integrità Strutturale  
T-stress is used as an important constraint parameter in the fracture analysis.  ...  The T-stress results obtained in the present analysis together with corresponding K I values can be used for analysis of constraint effects in a fracture specimen.  ...  Hence, it is required to conduct 3D analysis to completely assess the constraint issues in a fracture specimen having finite thickness.  ... 
doi:10.3221/igf-esis.08.04 fatcat:vjxvv6vdarhpze7xwdsjkhcwhe

Data-Driven Flower Petal Modeling with Botany Priors

Chenxi Zhang, Mao Ye, Bo Fu, Ruigang Yang
2014 2014 IEEE Conference on Computer Vision and Pattern Recognition  
In this paper we focus on the 3D modeling of flower, in particular the petals.  ...  The complex structure, severe occlusions, and wide variations make the reconstruction of their 3D models a challenging task.  ...  Acknowledgement This work is supported in part by US National Science Foundation grants IIS-1231545 and IIS-1208420.  ... 
doi:10.1109/cvpr.2014.87 dblp:conf/cvpr/ZhangYFY14 fatcat:d3akzk675nhjdk74dnropkjv6m

A retargeting method for stereoscopic 3D video

Yi Liu, Lifeng Sun, Shiqiang Yang
2015 Computational Visual Media  
Then, to maintain depth mapping stability, we model disparity variation energies to constraint the disparity range both in spatial and temporal domains.  ...  We propose a disparity-constrained retargeting method for stereoscopic 3D video, which simultaneously resizes a binocular video to a new aspect ratio and remaps the depth to the perceptual comfort zone  ...  Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s)  ... 
doi:10.1007/s41095-015-0016-2 fatcat:q73jfhiawfairhwecldhnz2nku

Neural Process Reconstruction from Sparse User Scribbles [chapter]

Mike Roberts, Won-Ki Jeong, Amelio Vázquez-Reina, Markus Unger, Horst Bischof, Jeff Lichtman, Hanspeter Pfister
2011 Lecture Notes in Computer Science  
Our method takes advantage of sparse scribble annotations provided by the user to guide a 3D variational segmentation model, thereby allowing our method to globally optimally enforce 3D geometric constraints  ...  Moreover, we leverage a novel algorithm for propagating segmentation constraints through the image stack via optimal volumetric pathways, thereby allowing our method to compute highly accurate 3D segmentations  ...  We compute the final 3D segmentation by globally refining the volumetric pathway according to an anisotropic variational segmentation model that aligns with strong in-plane image edges and enforces 3D  ... 
doi:10.1007/978-3-642-23623-5_78 fatcat:jckvmjj2hnghxp2xoxvgtjdtvm

Manhattan and Piecewise-Planar Constraints for Dense Monocular Mapping

Alejo Concha, Wajahat Hussain, Luis Montano, Javier Civera
2014 Robotics: Science and Systems X  
This paper presents a variational formulation for real-time dense 3D mapping from a RGB monocular sequence that incorporates Manhattan and piecewise-planar constraints in indoor and outdoor man-made scenes  ...  Our experiments include the largest map produced by variational methods from a RGB sequence and demonstrate a reduction in the median depth error up to a factor 5×.  ...  CONCLUSION In this paper we have presented an algorithm that integrates Manhattan and piecewise-planar constraints into a variational formulation for realtime dense 3D mapping from a RGB camera.  ... 
doi:10.15607/rss.2014.x.016 dblp:conf/rss/ConchaHMC14 fatcat:53yjsni2r5gh7p6jxrcklt5t7m

Fast and Controllable 3D Modelling From Silhouettes [article]

Mukta Prasad, Andrew Fitzgibbon, Andrew Zisserman
2005 Eurographics State of the Art Reports  
We show that a variety of editing operations—which can be defined either in the image or in 3D—can also be expressed as linear constraints on the 3D shape parameters.  ...  previously appeared in the large literature on the shape-from-silhouette problem.  ...  Constrained variational surfaces We seek a 3D surface r : [0, 1] 2 → R 3 , which is as smooth as possible while obeying user-specified constraints.  ... 
doi:10.2312/egs.20051011 fatcat:2prmmxa26ncirhcnmp3ws2g34m
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