Chloé Paliard, Eduardo Alvarado, D. Rohmer, Marie-Paule Cani
When walking on loose terrains, possibly covered with vegetation, the ground and grass should deform, but the character's gait should also change accordingly. We propose a method for modeling such two-ways interactions in real-time. We first complement a layered character model by a high-level controller, which uses position and angular velocity inputs to improve dynamic oscillations when walking on various slopes. Secondly, at a refined level, the feet are set to locally deform the ground and surrounding vegetation using efficient procedural functions, while the character's response to such deformations is computed through adapted inverse kinematics. While simple to set up, our method is generic enough to adapt to any character morphology. Moreover, its ability to generate in real time, consistent gaits on a variety of loose grounds of arbitrary slope, possibly covered with grass, makes it an interesting solution to enhance films and games.
{"title":"Soft Walks: Real-Time, Two-Ways Interaction between a Character and Loose Grounds","authors":"Chloé Paliard, Eduardo Alvarado, D. Rohmer, Marie-Paule Cani","doi":"10.2312/EGS.20211019","DOIUrl":"https://doi.org/10.2312/EGS.20211019","url":null,"abstract":"When walking on loose terrains, possibly covered with vegetation, the ground and grass should deform, but the character's gait should also change accordingly. We propose a method for modeling such two-ways interactions in real-time. We first complement a layered character model by a high-level controller, which uses position and angular velocity inputs to improve dynamic oscillations when walking on various slopes. Secondly, at a refined level, the feet are set to locally deform the ground and surrounding vegetation using efficient procedural functions, while the character's response to such deformations is computed through adapted inverse kinematics. While simple to set up, our method is generic enough to adapt to any character morphology. Moreover, its ability to generate in real time, consistent gaits on a variety of loose grounds of arbitrary slope, possibly covered with grass, makes it an interesting solution to enhance films and games.","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"90 1","pages":"41-44"},"PeriodicalIF":0.0,"publicationDate":"2021-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82447487","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}
In this paper we present a framework for modeling cable-driven soft robots fabricated from silicone rubber an incompressible material. Our forward simulation model can use either the standard or the mixed formulation of the finite element method (FEM). The latter prevents volumetric locking for incompressible materials and is more accurate for low resolution meshes. Hence, we show that mixed FEM is well suited for estimating elastic parameters and simulator validation. We also introduce a cable actuation model using barycentric coordinates and then use it to solve some simple control problems. CCS Concepts • Computing methodologies → Physical simulation; • Computer systems organization → Robotics;
{"title":"Modeling and Actuation of Cable-driven Silicone Soft Robots","authors":"Mihai Frâncu","doi":"10.2312/EGS.20211011","DOIUrl":"https://doi.org/10.2312/EGS.20211011","url":null,"abstract":"In this paper we present a framework for modeling cable-driven soft robots fabricated from silicone rubber an incompressible material. Our forward simulation model can use either the standard or the mixed formulation of the finite element method (FEM). The latter prevents volumetric locking for incompressible materials and is more accurate for low resolution meshes. Hence, we show that mixed FEM is well suited for estimating elastic parameters and simulator validation. We also introduce a cable actuation model using barycentric coordinates and then use it to solve some simple control problems. CCS Concepts • Computing methodologies → Physical simulation; • Computer systems organization → Robotics;","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"151 1","pages":"9-12"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76839525","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}
We propose a new watertight representation of geometry for ray tracing highly complex scenes in a memory efficient manner. Polygon meshes in the scene are first converted into compressed grid primitives, which are represented by a base bilinear patch with quantized displacement vectors. Ray-scene intersections are then computed by efficiently decompressing these grids onthe-fly and intersecting the implicit triangles. Our representation requires just 5.4− 6.6 bytes per triangle for the combined geometry and acceleration structure, resulting in a 5−7× reduction in memory footprint compared to indexed triangle meshes. This is achieved with less than 15% increase in rendering time. CCS Concepts • Computing methodologies → Ray tracing; Visibility; Massively parallel algorithms;
{"title":"Ray Tracing Lossy Compressed Grid Primitives","authors":"Carsten Benthin, K. Vaidyanathan, Sven Woop","doi":"10.2312/EGS.20211009","DOIUrl":"https://doi.org/10.2312/EGS.20211009","url":null,"abstract":"We propose a new watertight representation of geometry for ray tracing highly complex scenes in a memory efficient manner. Polygon meshes in the scene are first converted into compressed grid primitives, which are represented by a base bilinear patch with quantized displacement vectors. Ray-scene intersections are then computed by efficiently decompressing these grids onthe-fly and intersecting the implicit triangles. Our representation requires just 5.4− 6.6 bytes per triangle for the combined geometry and acceleration structure, resulting in a 5−7× reduction in memory footprint compared to indexed triangle meshes. This is achieved with less than 15% increase in rendering time. CCS Concepts • Computing methodologies → Ray tracing; Visibility; Massively parallel algorithms;","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82221064","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}
Surveillance cameras are expected to work also in bad visibility conditions, which requires algorithmic solutions to improve the captured image and to eliminate image degradation caused by these weather conditions. Algorithms for such tasks belong to the field of computational photography and have been successful in eliminating haze, fog, motion blur, etc. This paper presents a simple algorithm to suppress rain or snow from single images. The algorithm uses energy minimization, and we propose a novel data term and a Bregman distance based regularization term reflecting the particular properties of precipitation.
{"title":"Bregman Approach to Single Image De-Raining","authors":"László Szirmay-Kalos, M. Tóth","doi":"10.2312/EGS.20211017","DOIUrl":"https://doi.org/10.2312/EGS.20211017","url":null,"abstract":"Surveillance cameras are expected to work also in bad visibility conditions, which requires algorithmic solutions to improve the captured image and to eliminate image degradation caused by these weather conditions. Algorithms for such tasks belong to the field of computational photography and have been successful in eliminating haze, fog, motion blur, etc. This paper presents a simple algorithm to suppress rain or snow from single images. The algorithm uses energy minimization, and we propose a novel data term and a Bregman distance based regularization term reflecting the particular properties of precipitation.","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"31 1","pages":"33-36"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88464152","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}
We present an end-to-end algorithm that can automatically rig a given 3D character such that it is ready for 3D animation. The animation of a virtual character requires the skeletal motion defined with bones and joints, and the corresponding deformation of the mesh represented with skin weights. While the conventional animation pipeline requires the initial 3D character to be in the predefined default pose, our pipeline can rig a 3D character in arbitrary pose. We handle the increased ambiguity by fixing the skeletal topology and solving for the full deformation space. After the skeletal positions and orientations are fully discovered, we can deform the provided 3D character into the default pose, from which we can animate the character with the help of recent motion-retargeting techniques. Our results show that we can successfully animate initially deformed characters, which was not possible with previous works. CCS Concepts • Computing methodologies → Motion processing; 3D imaging; Neural networks;
{"title":"Auto-rigging 3D Bipedal Characters in Arbitrarily Poses","authors":"Jeonghwan Kim, Hyeontae Son, Ji-Sang Bae, Y. Kim","doi":"10.2312/EGS.20211023","DOIUrl":"https://doi.org/10.2312/EGS.20211023","url":null,"abstract":"We present an end-to-end algorithm that can automatically rig a given 3D character such that it is ready for 3D animation. The animation of a virtual character requires the skeletal motion defined with bones and joints, and the corresponding deformation of the mesh represented with skin weights. While the conventional animation pipeline requires the initial 3D character to be in the predefined default pose, our pipeline can rig a 3D character in arbitrary pose. We handle the increased ambiguity by fixing the skeletal topology and solving for the full deformation space. After the skeletal positions and orientations are fully discovered, we can deform the provided 3D character into the default pose, from which we can animate the character with the help of recent motion-retargeting techniques. Our results show that we can successfully animate initially deformed characters, which was not possible with previous works. CCS Concepts • Computing methodologies → Motion processing; 3D imaging; Neural networks;","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"73 1","pages":"57-60"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80500578","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}
P. Andersson, J. Nilsson, P. Shirley, T. Akenine-Möller
A new error metric targeting rendered high dynamic range images is presented. Our method computes a composite visualization over a number of low dynamic range error maps of exposure compensated and tone mapped image pairs with automatically computed, or manually provided, parameters. We argue that our new error maps predict errors substantially better than metrics previously used in rendering. Source code is released with the hope that our work can be a useful tool for future research. CCS Concepts • Computing methodologies → Rendering; • General and reference → Metrics;
{"title":"Visualizing Errors in Rendered High Dynamic Range Images","authors":"P. Andersson, J. Nilsson, P. Shirley, T. Akenine-Möller","doi":"10.2312/EGS.20211015","DOIUrl":"https://doi.org/10.2312/EGS.20211015","url":null,"abstract":"A new error metric targeting rendered high dynamic range images is presented. Our method computes a composite visualization over a number of low dynamic range error maps of exposure compensated and tone mapped image pairs with automatically computed, or manually provided, parameters. We argue that our new error maps predict errors substantially better than metrics previously used in rendering. Source code is released with the hope that our work can be a useful tool for future research. CCS Concepts • Computing methodologies → Rendering; • General and reference → Metrics;","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"20 1","pages":"25-28"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79042757","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}
Point sets are a widely used spatial data structure in computational and observational domains, e.g. in physics particle simulations, computer graphics or remote sensing. Algorithms typically operate in local neighborhoods of point sets, for computing physical states, surface reconstructions, etc. We present a visualization technique based on multi-scale geometric features of such point clouds. We explore properties of different choices on the underlying weighted co-variance neighborhood descriptor, illustrated on different point set geometries and for varying noise levels. The impact of different weighting functions and tensor centroids, as well as point set features and noise levels becomes visible in the rotation-invariant feature images. We compare to a curvature based scale space visualization method and, finally, show how features in real-world LiDAR data can be inspected by images created with our approach in an interactive tool. In contrast to the curvature based approach, with our method line structures are highlighted over growing scales, with clear border regions to planar or spherical geometric structures. CCS Concepts • Human-centered computing → Visual analytics; • Computing methodologies → Point-based models;
{"title":"Visual Analysis of Point Cloud Neighborhoods via Multi-Scale Geometric Measures","authors":"Marcel Ritter, D. Schiffner, M. Harders","doi":"10.2312/EGS.20211024","DOIUrl":"https://doi.org/10.2312/EGS.20211024","url":null,"abstract":"Point sets are a widely used spatial data structure in computational and observational domains, e.g. in physics particle simulations, computer graphics or remote sensing. Algorithms typically operate in local neighborhoods of point sets, for computing physical states, surface reconstructions, etc. We present a visualization technique based on multi-scale geometric features of such point clouds. We explore properties of different choices on the underlying weighted co-variance neighborhood descriptor, illustrated on different point set geometries and for varying noise levels. The impact of different weighting functions and tensor centroids, as well as point set features and noise levels becomes visible in the rotation-invariant feature images. We compare to a curvature based scale space visualization method and, finally, show how features in real-world LiDAR data can be inspected by images created with our approach in an interactive tool. In contrast to the curvature based approach, with our method line structures are highlighted over growing scales, with clear border regions to planar or spherical geometric structures. CCS Concepts • Human-centered computing → Visual analytics; • Computing methodologies → Point-based models;","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"55 1","pages":"61-64"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72952067","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}
An interesting way to explore curved spaces is to play games governed by the rules of non-Euclidean geometries. However, modeling tools and game engines are developed with Euclidean geometry in mind. This paper addresses the problem of porting a game from Euclidean to elliptic geometry. We consider primarily the geometric calculations and the transformation pipeline.
{"title":"Gaming in Elliptic Geometry","authors":"László Szirmay-Kalos, M. Magdics","doi":"10.2312/egs.20211010","DOIUrl":"https://doi.org/10.2312/egs.20211010","url":null,"abstract":"An interesting way to explore curved spaces is to play games governed by the rules of non-Euclidean geometries. However, modeling tools and game engines are developed with Euclidean geometry in mind. This paper addresses the problem of porting a game from Euclidean to elliptic geometry. We consider primarily the geometric calculations and the transformation pipeline.","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"16 1","pages":"5-8"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85148842","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}
In surgical training simulators, where various organ surfaces make up the majority of the scene, the visual appearance is highly dependent on the quality of the surface textures. Blood vessels are an important detail in this; they need to be incorporated into an organ’s texture. Moreover, the actual blood vessel geometries also have to be part of the simulated surgical procedure itself, e.g. during cutting. Since the manual creation of vessel geometry or branching details on textures is highly tedious, an automatic synthesis technique capable of generating a wide range of blood vessel patterns is needed. We propose a new synthesis approach based on the space colonization algorithm. As extension, physiological constraints on the proliferation of branches are enforced to create realistic vascular structures. Our framework is capable of generating three-dimensional blood vessel networks in a matter of milliseconds, thus allowing a 3D modeller to tweak parameters in real-time to obtain a desired appearance.
{"title":"Interactive Synthesis of 3D Geometries of Blood Vessels","authors":"Nikolaus Rauch, M. Harders","doi":"10.2312/EGS.20211012","DOIUrl":"https://doi.org/10.2312/EGS.20211012","url":null,"abstract":"In surgical training simulators, where various organ surfaces make up the majority of the scene, the visual appearance is highly dependent on the quality of the surface textures. Blood vessels are an important detail in this; they need to be incorporated into an organ’s texture. Moreover, the actual blood vessel geometries also have to be part of the simulated surgical procedure itself, e.g. during cutting. Since the manual creation of vessel geometry or branching details on textures is highly tedious, an automatic synthesis technique capable of generating a wide range of blood vessel patterns is needed. We propose a new synthesis approach based on the space colonization algorithm. As extension, physiological constraints on the proliferation of branches are enforced to create realistic vascular structures. Our framework is capable of generating three-dimensional blood vessel networks in a matter of milliseconds, thus allowing a 3D modeller to tweak parameters in real-time to obtain a desired appearance.","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"174 1","pages":"13-16"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76924378","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}
Three-dimensional scanning technology recently becomes widely available to the public. However, it is difficult to simulate clothing deformation from the scanned people because scanned data lacks information required for the clothing simulation. In this paper, we present a technique to estimate clothing patterns from a scanned person in cloth. Our technique uses image-based deep learning to estimate the type of pattern on the projected image. The key contribution is converting image-based inference into three-dimensional clothing pattern estimation. We evaluate our technique by applying our technique to an actual scan. CCS Concepts • Computing methodologies → Shape modeling; Neural networks;
{"title":"Data-driven Garment Pattern Estimation from 3D Geometries","authors":"Chihiro Goto, Nobuyuki Umetani","doi":"10.2312/EGS.20211013","DOIUrl":"https://doi.org/10.2312/EGS.20211013","url":null,"abstract":"Three-dimensional scanning technology recently becomes widely available to the public. However, it is difficult to simulate clothing deformation from the scanned people because scanned data lacks information required for the clothing simulation. In this paper, we present a technique to estimate clothing patterns from a scanned person in cloth. Our technique uses image-based deep learning to estimate the type of pattern on the projected image. The key contribution is converting image-based inference into three-dimensional clothing pattern estimation. We evaluate our technique by applying our technique to an actual scan. CCS Concepts • Computing methodologies → Shape modeling; Neural networks;","PeriodicalId":72958,"journal":{"name":"Eurographics ... Workshop on 3D Object Retrieval : EG 3DOR. Eurographics Workshop on 3D Object Retrieval","volume":"52 1","pages":"17-20"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83973216","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}