{"title":"Building efficient, accurate character skins from examples","authors":"Alex Mohr, Michael Gleicher","doi":"10.1145/1201775.882308","DOIUrl":"https://doi.org/10.1145/1201775.882308","url":null,"abstract":"Good character animation requires convincing skin deformations including subtleties and details like muscle bulges. Such effects are typically created in commercial animation packages which provide very general and powerful tools. While these systems are convenient and flexible for artists, the generality often leads to characters that are slow to compute or that require a substantial amount of memory and thus cannot be used in interactive systems. Instead, interactive systems restrict artists to a specific character deformation model which is fast and memory efficient but is notoriously difficult to author and can suffer from many deformation artifacts. This paper presents an automated framework that allows character artists to use the full complement of tools in high-end systems to create characters for interactive systems. Our method starts with an arbitrarily rigged character in an animation system. A set of examples is exported, consisting of skeleton configurations paired with the deformed geometry as static meshes. Using these examples, we fit the parameters of a deformation model that best approximates the original data yet remains fast to compute and compact in memory.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127098404","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}
Peter-Pike J. Sloan, Xinguo Liu, H. Shum, John M. Snyder
{"title":"Bi-scale radiance transfer","authors":"Peter-Pike J. Sloan, Xinguo Liu, H. Shum, John M. Snyder","doi":"10.1145/1201775.882279","DOIUrl":"https://doi.org/10.1145/1201775.882279","url":null,"abstract":"Radiance transfer represents how generic source lighting is shadowed and scattered by an object to produce view-dependent appearance. We generalize by rendering transfer at two scales. A macro-scale is coarsely sampled over an object's surface, providing global effects like shadows cast from an arm onto a body. A meso-scale is finely sampled over a small patch to provide local texture. Low-order (25D) spherical harmonics represent low-frequency lighting dependence for both scales. To render, a coefficient vector representing distant source lighting is first transformed at the macro-scale by a matrix at each vertex of a coarse mesh. The resulting vectors represent a spatially-varying hemisphere of lighting incident to the meso-scale. A 4D function, called a radiance transfer texture (RTT), then specifies the surface's meso-scale response to each lighting basis component, as a function of a spatial index and a view direction. Finally, a 25D dot product of the macro-scale result vector with the vector looked up from the RTT performs the correct shading integral. We use an id map to place RTT samples from a small patch over the entire object; only two scalars are specified at high spatial resolution. Results show that bi-scale decomposition makes preprocessing practical and efficiently renders self-shadowing and interreflection effects from dynamic, low-frequency light sources at both scales.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126721506","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}
Adrien Treuille, A. McNamara, Zoran Popovic, J. Stam
{"title":"Keyframe control of smoke simulations","authors":"Adrien Treuille, A. McNamara, Zoran Popovic, J. Stam","doi":"10.1145/1201775.882337","DOIUrl":"https://doi.org/10.1145/1201775.882337","url":null,"abstract":"We describe a method for controlling smoke simulations through user-specified keyframes. To achieve the desired behavior, a continuous quasi-Newton optimization solves for appropriate \"wind\" forces to be applied to the underlying velocity field throughout the simulation. The cornerstone of our approach is a method to efficiently compute exact derivatives through the steps of a fluid simulation. We formulate an objective function corresponding to how well a simulation matches the user's keyframes, and use the derivatives to solve for force parameters that minimize this function. For animations with several keyframes, we present a novel multiple-shooting approach. By splitting large problems into smaller overlapping subproblems, we greatly speed up the optimization process while avoiding certain local minima.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"335 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129419808","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}
M. Goesele, Xavier Granier, W. Heidrich, H. Seidel
{"title":"Accurate light source acquisition and rendering","authors":"M. Goesele, Xavier Granier, W. Heidrich, H. Seidel","doi":"10.1145/1201775.882316","DOIUrl":"https://doi.org/10.1145/1201775.882316","url":null,"abstract":"Realistic image synthesis requires both complex and realistic models of real-world light sources and efficient rendering algorithms to deal with them. In this paper, we describe a processing pipeline for dealing with complex light sources from acquisition to global illumination rendering. We carefully design optical filters to guarantee high precision measurements of real-world light sources. We discuss two practically feasible setups that allow us to measure light sources with different characteristics. Finally, we introduce an efficient importance sampling algorithm for our representation that can be used, for example, in conjunction with Photon Maps.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128594163","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}
N. Tsumura, Nobutoshi Ojima, Kayoko Sato, M. Shiraishi, Hideto Shimizu, Hirohide Nabeshima, S. Akazaki, K. Hori, Y. Miyake
{"title":"Image-based skin color and texture analysis/synthesis by extracting hemoglobin and melanin information in the skin","authors":"N. Tsumura, Nobutoshi Ojima, Kayoko Sato, M. Shiraishi, Hideto Shimizu, Hirohide Nabeshima, S. Akazaki, K. Hori, Y. Miyake","doi":"10.1145/1201775.882344","DOIUrl":"https://doi.org/10.1145/1201775.882344","url":null,"abstract":"This paper proposes an E-cosmetic function for digital images based on physics and physiologically-based image processing. A practical skin color and texture analysis/synthesis technique is introduced for this E-cosmetic function. Shading on the face is removed by a simple color vector analysis in the optical density domain as an inverse lighting technique. The image without shading is analyzed by a previously introduced technique that extracts hemoglobin and melanin components by independent component analysis. Experimental results using UV-B irradiation and the application of methyl nicotinate on the arms support the physiological validity of the analysis and the effectiveness of the proposed shading removal. We synthesized the way facial images changed due to tanning or alcohol consumption, and compared the synthesized images with images of actual changes in skin color. The comparison shows an excellent match between the synthesized and actual images of changes due to tanning and alcohol consumption. We also proposed a technique to synthesize the change of texture in pigment due to aging or the application of cosmetics. The pyramid-based texture analysis/synthesis technique was used for the spatial processing of texture. Using the proposed technique, we could realistically change the skin color and texture of a 50 year-old woman to that of a 20 year-old woman.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121431266","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}
{"title":"Clothing manipulation","authors":"T. Igarashi, J. Hughes","doi":"10.1145/1201775.882328","DOIUrl":"https://doi.org/10.1145/1201775.882328","url":null,"abstract":"This paper presents interaction techniques (and the underlying implementations) for putting clothes on a 3D character and manipulating them. The user paints freeform marks on the clothes and corresponding marks on the 3D character; the system then puts the clothes around the body so that corresponding marks match. Internally, the system grows the clothes on the body surface around the marks while maintaining basic cloth constraints via simple relaxation steps. The entire computation takes a few seconds . After that, the user can adjust the placement of the clothes by an enhanced dragging operation. Unlike standard dragging where the user moves a set of vertices in a single direction in 3D space, our dragging operation moves the cloth along the body surface to make possible more flexible operations. The user can apply pushpins to fix certain cloth points during dragging. The techniques are ideal for specifying an initial cloth configuration before applying a more sophisticated cloth simulation.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130115905","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}
{"title":"Graphics for the masses: a hardware rasterization architecture for mobile phones","authors":"T. Akenine-Möller, Jacob Ström","doi":"10.1145/1201775.882348","DOIUrl":"https://doi.org/10.1145/1201775.882348","url":null,"abstract":"The mobile phone is one of the most widespread devices with rendering capabilities. Those capabilities have been very limited because the resources on such devices are extremely scarce; small amounts of memory, little bandwidth, little chip area dedicated for special purposes, and limited power consumption. The small display resolutions present a further challenge; the angle subtended by a pixel is relatively large, and therefore reasonably high quality rendering is needed to generate high fidelity images.To increase the mobile rendering capabilities, we propose a new hardware architecture for rasterizing textured triangles. Our architecture focuses on saving memory bandwidth, since an external memory access typically is one of the most energy-consuming operations, and because mobile phones need to use as little power as possible. Therefore, our system includes three new key innovations: I) an inexpensive multisampling scheme that gives relatively high quality at the same cost of previous inexpensive schemes, II) a texture minification system, including texture compression, which gives quality relatively close to trilinear mipmapping at the cost of 1.33 32-bit memory accesses on average, III) a scanline-based culling scheme that avoids a significant amount of z-buffer reads, and that only requires one context. Software simulations show that these three innovations together significantly reduce the memory bandwidth, and thus also the power consumption.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"54 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132575536","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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