H. Fuchs, Jack Goldfeather, J. Hultquist, S. Spach, J. D. Austin, F. Brooks, J. Eyles, J. Poulton
Pixel-planes is a logic-enhanced memory system for raster graphics and imaging. Although each pixel-memory is enhanced with a one-bit ALU, the system's real power comes from a tree of one-bit adders that can evaluate linear expressions Ax+By+C for every pixel (x,y) simultaneously, as fast as the ALUs and the memory circuits can accept the results. We and others have begun to develop a variety of algorithms that exploit this fast linear expression evaluation capability. In this paper we report some of those results. Illustrated in this paper is a sample image from a small working prototype of the Pixel-planes hardware and a variety of images from simulations of a full-scale system. Timing estimates indicate that 30,000 smooth shaded triangles can be generated per second, or 21,000 smooth-shaded and shadowed triangles can be generated per second, or over 25,000 shaded spheres can be generated per second. Image-enhancement by adaptive histogram equalization can be performed within 4 seconds on a 512x512 image.
{"title":"Fast spheres, shadows, textures, transparencies, and imgage enhancements in pixel-planes","authors":"H. Fuchs, Jack Goldfeather, J. Hultquist, S. Spach, J. D. Austin, F. Brooks, J. Eyles, J. Poulton","doi":"10.1145/325334.325205","DOIUrl":"https://doi.org/10.1145/325334.325205","url":null,"abstract":"Pixel-planes is a logic-enhanced memory system for raster graphics and imaging. Although each pixel-memory is enhanced with a one-bit ALU, the system's real power comes from a tree of one-bit adders that can evaluate linear expressions Ax+By+C for every pixel (x,y) simultaneously, as fast as the ALUs and the memory circuits can accept the results. We and others have begun to develop a variety of algorithms that exploit this fast linear expression evaluation capability. In this paper we report some of those results. Illustrated in this paper is a sample image from a small working prototype of the Pixel-planes hardware and a variety of images from simulations of a full-scale system. Timing estimates indicate that 30,000 smooth shaded triangles can be generated per second, or 21,000 smooth-shaded and shadowed triangles can be generated per second, or over 25,000 shaded spheres can be generated per second. Image-enhancement by adaptive histogram equalization can be performed within 4 seconds on a 512x512 image.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126057755","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}
This paper presents a comprehensive method to calculate object to object diffuse reflections within complex environments containing hidden surfaces and shadows. In essence, each object in the environment is treated as a secondary light source. The method provides an accurate representation of the "diffuse" and "ambient" terms found in typical image synthesis algorithms. The phenomena of "color bleeding" from one surface to another, shading within shadow envelopes, and penumbras along shadow boundaries are accurately reproduced. Additional advantages result because computations are indepedent of viewer position. This allows the efficient rendering of multiple views of the same scene for dynamic sequences. Light sources can be modulated and object reflectivities can be changed, with minimal extra computation. The procedures extend the radiosity method beyond the bounds previously imposed.
{"title":"The hemi-cube: a radiosity solution for complex environments","authors":"Michael F. Cohen, D. Greenberg","doi":"10.1145/325334.325171","DOIUrl":"https://doi.org/10.1145/325334.325171","url":null,"abstract":"This paper presents a comprehensive method to calculate object to object diffuse reflections within complex environments containing hidden surfaces and shadows. In essence, each object in the environment is treated as a secondary light source. The method provides an accurate representation of the \"diffuse\" and \"ambient\" terms found in typical image synthesis algorithms. The phenomena of \"color bleeding\" from one surface to another, shading within shadow envelopes, and penumbras along shadow boundaries are accurately reproduced. Additional advantages result because computations are indepedent of viewer position. This allows the efficient rendering of multiple views of the same scene for dynamic sequences. Light sources can be modulated and object reflectivities can be changed, with minimal extra computation. The procedures extend the radiosity method beyond the bounds previously imposed.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129908272","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}
Most volume modelling systems are very limited in the complexity of the surfaces which they support. This is satisfactory for basic models of most mechanical components, since the functional surfaces are not usually complex. However, there are often blends between simple base surfaces. This paper presents a technique appropriate for blend definition and profile control. A discussion of blend conics is used to develop analogous surfaces for use in typical volume modelling systems. These surfaces are then used to set theoretically define bounded volumes for fillets and chamfers. Empirical results show that the method described suits many engineering applications.
{"title":"Blend surfaces for set theoretic volume modelling systems","authors":"A. Middleditch, Kenneth H. Sears","doi":"10.1145/325334.325231","DOIUrl":"https://doi.org/10.1145/325334.325231","url":null,"abstract":"Most volume modelling systems are very limited in the complexity of the surfaces which they support. This is satisfactory for basic models of most mechanical components, since the functional surfaces are not usually complex. However, there are often blends between simple base surfaces. This paper presents a technique appropriate for blend definition and profile control. A discussion of blend conics is used to develop analogous surfaces for use in typical volume modelling systems. These surfaces are then used to set theoretically define bounded volumes for fillets and chamfers. Empirical results show that the method described suits many engineering applications.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125473081","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}
Triangulation is an efficient way to simplify and unify interference problems, such as hidden line and surface elimination and Boolean shape operations in solid modeling. Almost all of the processing relevant to a triangle can be performed by computing some 4 x 4 determinants. The author proposes a hardware processor (TRIANGLE PROCESSOR) that quickly intersects a triangle with a point, a line segment, or another triangle. Various applications of the TRIANGLE PROCESSOR are explained in this paper, including applications to face and volume triangulations.The author stresses that the triangulation approach and the TRIANGLE PROCESSOR simplify, speed up and unify various types of processing relating to interference.
{"title":"A unified approach to interference problems using a triangle processor","authors":"F. Yamaguchi","doi":"10.1145/325334.325224","DOIUrl":"https://doi.org/10.1145/325334.325224","url":null,"abstract":"Triangulation is an efficient way to simplify and unify interference problems, such as hidden line and surface elimination and Boolean shape operations in solid modeling. Almost all of the processing relevant to a triangle can be performed by computing some 4 x 4 determinants. The author proposes a hardware processor (TRIANGLE PROCESSOR) that quickly intersects a triangle with a point, a line segment, or another triangle. Various applications of the TRIANGLE PROCESSOR are explained in this paper, including applications to face and volume triangulations.The author stresses that the triangulation approach and the TRIANGLE PROCESSOR simplify, speed up and unify various types of processing relating to interference.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"2645 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127426054","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}
A discussion is presented of the relationship between two solid representation schemes: constructive solid geometry (CSG trees) and recursive spatial subdivision exemplified by the bintree, a generalization of the quadtree and octree. Detailed algorithms are developed and analyzed for evaluating CSG trees by bintree conversion, i.e., by determining explicitly which parts of space are solid and which empty. These techniques enable the addition of the time dimension and motion to the approximate analysis of CSG trees in a simple manner to solve problems such as dynamic interference detection. For "well-behaved" CSG trees, the execution time of the conversion algorithm is directly related to the spatial complexity of the object represented by the CSG tree (i.e., asymptotically it is proportional to the number of bintree nodes as the resolution increases). The set of well-behaved CSG trees includes all trees that define multidimensional polyhedra in a manner that does not give rise to tangential intersections at CSG tree nodes.
{"title":"Bintrees, CSG trees, and time","authors":"H. Samet, Markku Tamminen","doi":"10.1145/325334.325211","DOIUrl":"https://doi.org/10.1145/325334.325211","url":null,"abstract":"A discussion is presented of the relationship between two solid representation schemes: constructive solid geometry (CSG trees) and recursive spatial subdivision exemplified by the bintree, a generalization of the quadtree and octree. Detailed algorithms are developed and analyzed for evaluating CSG trees by bintree conversion, i.e., by determining explicitly which parts of space are solid and which empty. These techniques enable the addition of the time dimension and motion to the approximate analysis of CSG trees in a simple manner to solve problems such as dynamic interference detection. For \"well-behaved\" CSG trees, the execution time of the conversion algorithm is directly related to the spatial complexity of the object represented by the CSG tree (i.e., asymptotically it is proportional to the number of bintree nodes as the resolution increases). The set of well-behaved CSG trees includes all trees that define multidimensional polyhedra in a manner that does not give rise to tangential intersections at CSG tree nodes.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124870534","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}
Zsuzsanna Molnar, P. Buning, P. Doenges, R. Langridge, T. Lasinski, Randy Smith
Flight simulation was the first well-known real-time simulation application using computer graphics. New computer architectures, combined with fast interactive graphics, extend the scope of simulation to encompass ever more realistic visual simulation as well as the modeling of objects and processes: computer prototyping. Panelists will discuss evolutionary trends, costs and effectiveness of real-time simulation citing examples from flight simulation, drug design, wind tunnel simulation, the testing of on-the-road car behavior and robotics.
{"title":"Real-time simulation in the real world (panel session)","authors":"Zsuzsanna Molnar, P. Buning, P. Doenges, R. Langridge, T. Lasinski, Randy Smith","doi":"10.1145/325334.325259","DOIUrl":"https://doi.org/10.1145/325334.325259","url":null,"abstract":"Flight simulation was the first well-known real-time simulation application using computer graphics. New computer architectures, combined with fast interactive graphics, extend the scope of simulation to encompass ever more realistic visual simulation as well as the modeling of objects and processes: computer prototyping. Panelists will discuss evolutionary trends, costs and effectiveness of real-time simulation citing examples from flight simulation, drug design, wind tunnel simulation, the testing of on-the-road car behavior and robotics.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132367843","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}
Touch-sensitive tablets and their use in human-computer interaction are discussed. It is shown that such devices have some important properties that differentiate them from other input devices (such as mice and joysticks). The analysis serves two purposes: (1) it sheds light on touch tablets, and (2) it demonstrates how other devices might be approached. Three specific distinctions between touch tablets and one button mice are drawn. These concern the signaling of events, multiple point sensing and the use of templates. These distinctions are reinforced, and possible uses of touch tablets are illustrated, in an example application. Potential enhancements to touch tablets and other input devices are discussed, as are some inherent problems. The paper concludes with recommendations for future work.
{"title":"Issues and techniques in touch-sensitive tablet input","authors":"W. Buxton, R. Hill, Peter Rowley","doi":"10.1145/325334.325239","DOIUrl":"https://doi.org/10.1145/325334.325239","url":null,"abstract":"Touch-sensitive tablets and their use in human-computer interaction are discussed. It is shown that such devices have some important properties that differentiate them from other input devices (such as mice and joysticks). The analysis serves two purposes: (1) it sheds light on touch tablets, and (2) it demonstrates how other devices might be approached. Three specific distinctions between touch tablets and one button mice are drawn. These concern the signaling of events, multiple point sensing and the use of templates. These distinctions are reinforced, and possible uses of touch tablets are illustrated, in an example application. Potential enhancements to touch tablets and other input devices are discussed, as are some inherent problems. The paper concludes with recommendations for future work.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131289238","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}
R. M. Dunn, S. Bly, R. Guedj, William J. Poduska, W. Lasser
Beginning with Sketchpad and continuing to Macintosh and beyond, designers and users of interactive graphics systems and applications have refined the nature of the working graphical, interface between a person and a computer. The panel will trace the changing uses of graphical symbols and icons; address the evolution of concurrency in windows, menus and task activation; examine mechanisms for gaining attention and prompting for reactions; and focus on reducing visual, physical and psychological stress via improved screen design and applied principles of graphical presentation.
{"title":"Issues at the interface (panel session): an historical trace of prompting, concurrency, signification and ease of use","authors":"R. M. Dunn, S. Bly, R. Guedj, William J. Poduska, W. Lasser","doi":"10.1145/325334.325253","DOIUrl":"https://doi.org/10.1145/325334.325253","url":null,"abstract":"Beginning with Sketchpad and continuing to Macintosh and beyond, designers and users of interactive graphics systems and applications have refined the nature of the working graphical, interface between a person and a computer. The panel will trace the changing uses of graphical symbols and icons; address the evolution of concurrency in windows, menus and task activation; examine mechanisms for gaining attention and prompting for reactions; and focus on reducing visual, physical and psychological stress via improved screen design and applied principles of graphical presentation.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133866248","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}
A number of techniques are presented for making conic splines more effective for 2D computer graphics. We give a brief account of the theory of conic splines oriented to computer graphics. We make Pitteway's algorithm exact, and repair an "aliasing" problem that has plagued the algorithm since its introduction in 1967. The curvature-matching problem for conics is solved by way of a simple formula for curvature at an endpoint which permits curvature to be matched exactly at non-inflectior points and more closely than was previously realized possible at points of inflection. A formula for minimum-curvature-variation of conic splines is given. These techniques provide additional support for Pavlidis' position [6] that conics can often be very effective as splines.The work was motivated by, and provides much of the foundation for, an implementation of conic splines at Sun Microsystems as part of Sun's Pixrect graphics package, the lowest layer of Sun's graphics support.
{"title":"Techniques for conic splines","authors":"V. Pratt","doi":"10.1145/325334.325225","DOIUrl":"https://doi.org/10.1145/325334.325225","url":null,"abstract":"A number of techniques are presented for making conic splines more effective for 2D computer graphics. We give a brief account of the theory of conic splines oriented to computer graphics. We make Pitteway's algorithm exact, and repair an \"aliasing\" problem that has plagued the algorithm since its introduction in 1967. The curvature-matching problem for conics is solved by way of a simple formula for curvature at an endpoint which permits curvature to be matched exactly at non-inflectior points and more closely than was previously realized possible at points of inflection. A formula for minimum-curvature-variation of conic splines is given. These techniques provide additional support for Pavlidis' position [6] that conics can often be very effective as splines.The work was motivated by, and provides much of the foundation for, an implementation of conic splines at Sun Microsystems as part of Sun's Pixrect graphics package, the lowest layer of Sun's graphics support.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123853116","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}
Cook, Porter, and Carpenter coined the phrase "distributed ray tracing" to describe a technique for using each ray of a super-sampled ray tracing procedure as a sample in several dimensions to achieve effects such as penumbras and motion blur in addition to spatial anti-aliasing. The shade to be displayed at a pixel is a weighted integral of the image function. The purpose of using many rays per pixel is to estimate the value of this integral. In this work, a relationship between the number of sample rays and the quality of the estimate of this integral is derived. Furthermore, the number of rays required does not depend on the dimensionality of the space being sampled, but only on the variance of the multi-dimensional image function. The algorithm has been optimized through the use of statistical testing and stratified sampling.
{"title":"Statistically optimized sampling for distributed ray tracing","authors":"Mark E. Lee, R. Redner, S. Uselton","doi":"10.1145/325334.325179","DOIUrl":"https://doi.org/10.1145/325334.325179","url":null,"abstract":"Cook, Porter, and Carpenter coined the phrase \"distributed ray tracing\" to describe a technique for using each ray of a super-sampled ray tracing procedure as a sample in several dimensions to achieve effects such as penumbras and motion blur in addition to spatial anti-aliasing. The shade to be displayed at a pixel is a weighted integral of the image function. The purpose of using many rays per pixel is to estimate the value of this integral. In this work, a relationship between the number of sample rays and the quality of the estimate of this integral is derived. Furthermore, the number of rays required does not depend on the dimensionality of the space being sampled, but only on the variance of the multi-dimensional image function. The algorithm has been optimized through the use of statistical testing and stratified sampling.","PeriodicalId":163416,"journal":{"name":"Proceedings of the 12th annual conference on Computer graphics and interactive techniques","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130448925","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}