Although fractal models of natural phenomena have received much attention recently, there are other models of complex natural objects which have been around longer in Computer Imagery but are not widely known. These are procedural models of plants and trees. An interesting class of these models is presented here which handles plant growth, sports an efficient data representation, and has a high “database amplification” factor. It is based on an extension of the well-known formal languages of symbol strings to the lesser-known formal languages of labeled graphs. It is so tempting to describe these plant models as “fractal” that the similarities of this class of models with fractal models are explored in an attempt at rapprochement. The models are not fractal so the common parts of fractal theory and plant theory are abstracted to form a class of objects, the graftals. This class may prove to be of great interest to the future of Computer Imagery. Determinism is shown to provide adequate complexity, whereas randomness is only convenient and often inefficient. Finally, a nonfractal, nongraftal family of trees by Bill Reeves is introduced to emphasize some of the paper's nongrammatical themes.
{"title":"Plants, fractals, and formal languages","authors":"A. R. Smith","doi":"10.1145/800031.808571","DOIUrl":"https://doi.org/10.1145/800031.808571","url":null,"abstract":"Although fractal models of natural phenomena have received much attention recently, there are other models of complex natural objects which have been around longer in Computer Imagery but are not widely known. These are procedural models of plants and trees. An interesting class of these models is presented here which handles plant growth, sports an efficient data representation, and has a high “database amplification” factor. It is based on an extension of the well-known formal languages of symbol strings to the lesser-known formal languages of labeled graphs. It is so tempting to describe these plant models as “fractal” that the similarities of this class of models with fractal models are explored in an attempt at rapprochement. The models are not fractal so the common parts of fractal theory and plant theory are abstracted to form a class of objects, the graftals. This class may prove to be of great interest to the future of Computer Imagery. Determinism is shown to provide adequate complexity, whereas randomness is only convenient and often inefficient. Finally, a nonfractal, nongraftal family of trees by Bill Reeves is introduced to emphasize some of the paper's nongrammatical themes.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126553874","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 algorithm for converting from the boundary representation of a solid to the corresponding octree model. The algorithm utilizes an efficient new connected components labeling technique. A novelty of the method is the demonstration that all processing can be performed directly on linear quad and octree encodings. We illustrate the use of the algorithm by an application to geometric mine modeling and verify its performance by analysis and practical experiments.
{"title":"Efficient octree conversion by connectivity labeling","authors":"Markku Tamminen, H. Samet","doi":"10.1145/800031.808576","DOIUrl":"https://doi.org/10.1145/800031.808576","url":null,"abstract":"We present an algorithm for converting from the boundary representation of a solid to the corresponding octree model. The algorithm utilizes an efficient new connected components labeling technique. A novelty of the method is the demonstration that all processing can be performed directly on linear quad and octree encodings. We illustrate the use of the algorithm by an application to geometric mine modeling and verify its performance by analysis and practical experiments.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129562817","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}
Recent progress in Japanese computer-integrated manufacturing (CIM) includes the integration of computer graphics, database management systems, local area networks, robotics and software engineering technology. This panel will discuss advanced CAD, CAM CAT (computer-aided testing) and FMS (flexible manufacturing systems) available in Japan. After the overview by the Chair Prof. Kunii, the basic CIM related researches to support industrial applications will be explained by Prof. Nakajima of the University of Tokyo. A wide spectrum of recent industrial advances and future trends in Japanese CIM are covered by four panelists from reputed manufacturers and users of CIM facilities and equipments. As one of the features of Japanese CIM, it will be noticed throughout the panel presentations and discussions that manufacturers always send out their products into the market after extensive internal use of them. Mr. Kubo of Hitachi Omika Work will present new networked CIM workstation. A typical example of very large CIM will be shown by Mr. Nakagawa of Mitsui Engineering and Shipbuilding. Very aggressive lines of products and plans are expected from Fanuc and will be presented by Mr. Inaba of GM Fanuo Robotics. Mr. Nishioka of Sharp will conclude the session explaining how he has developed and marketed very practical CIM successfully.
{"title":"Computer-integrated manufacturing in Japan (Panel)","authors":"T. Kunii","doi":"10.1145/800031.808574","DOIUrl":"https://doi.org/10.1145/800031.808574","url":null,"abstract":"Recent progress in Japanese computer-integrated manufacturing (CIM) includes the integration of computer graphics, database management systems, local area networks, robotics and software engineering technology. This panel will discuss advanced CAD, CAM CAT (computer-aided testing) and FMS (flexible manufacturing systems) available in Japan. After the overview by the Chair Prof. Kunii, the basic CIM related researches to support industrial applications will be explained by Prof. Nakajima of the University of Tokyo. A wide spectrum of recent industrial advances and future trends in Japanese CIM are covered by four panelists from reputed manufacturers and users of CIM facilities and equipments. As one of the features of Japanese CIM, it will be noticed throughout the panel presentations and discussions that manufacturers always send out their products into the market after extensive internal use of them. Mr. Kubo of Hitachi Omika Work will present new networked CIM workstation. A typical example of very large CIM will be shown by Mr. Nakagawa of Mitsui Engineering and Shipbuilding. Very aggressive lines of products and plans are expected from Fanuc and will be presented by Mr. Inaba of GM Fanuo Robotics. Mr. Nishioka of Sharp will conclude the session explaining how he has developed and marketed very practical CIM successfully.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133516869","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}
Methodologies, techniques and applications for the storage, retrieval and display of integrated graphics and text will be discussed. Current areas of interest include engineering drawings, CAD, publishing, graphics and databases, business graphics, office systems, cartography, typography and high quality text. This topic is at the leading edge of current developments and cost-effective applications will be examined. Dr. Rae Earnshaw, Chairman of the BCS Displays Group, will outline current needs and objectives for integrating graphics and text in the context of information processing and display, and indicate progress towards the long term goal of “what you see is what you print”.
{"title":"The storage, retrieval and display of integrated graphics and text (Panel)","authors":"R. Earnshaw","doi":"10.1145/800031.808607","DOIUrl":"https://doi.org/10.1145/800031.808607","url":null,"abstract":"Methodologies, techniques and applications for the storage, retrieval and display of integrated graphics and text will be discussed. Current areas of interest include engineering drawings, CAD, publishing, graphics and databases, business graphics, office systems, cartography, typography and high quality text. This topic is at the leading edge of current developments and cost-effective applications will be examined. Dr. Rae Earnshaw, Chairman of the BCS Displays Group, will outline current needs and objectives for integrating graphics and text in the context of information processing and display, and indicate progress towards the long term goal of “what you see is what you print”.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"303 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133600707","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}
Soft filling algorithms change the color of an anti-aliased region, maintaining the anti-aliasing of the region. The two published algorithms for soft filling work only if the foreground region is anti-aliased against a black background. This paper presents three new algorithms. The first fills against a region consisting of any two distinct colors, and is faster than the published algorithms on a pixel-by-pixel basis for an RGB frame buffer; the second fills against a region composed of three distinct colors; and the third fills against a region composed of four distinct colors. As the power of the algorithms increases, so do the number of assumptions they make, and the computational cost.
{"title":"A family of new algorithms for soft filling","authors":"K. Fishkin, B. Barsky","doi":"10.1145/800031.808604","DOIUrl":"https://doi.org/10.1145/800031.808604","url":null,"abstract":"Soft filling algorithms change the color of an anti-aliased region, maintaining the anti-aliasing of the region. The two published algorithms for soft filling work only if the foreground region is anti-aliased against a black background. This paper presents three new algorithms. The first fills against a region consisting of any two distinct colors, and is faster than the published algorithms on a pixel-by-pixel basis for an RGB frame buffer; the second fills against a region composed of three distinct colors; and the third fills against a region composed of four distinct colors. As the power of the algorithms increases, so do the number of assumptions they make, and the computational cost.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"125 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134004419","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}
The term “graphics dynamics” is used in this paper to describe a capability which permits the application programmer to specify a relationship between various graphics input devices and aspects of the graphics output presentation. Subsequent use of the input devices results in continuous real-time changes to the picture. An experimental graphics system is described, in which a powerful programmer's interface to graphics dynamics was implemented. This interface appears suitable for use as an extension to any of the existing standards and standards proposals, including, CORE, GKS, and PHIGS.
{"title":"A programmer's interface to graphics dynamics","authors":"J. Turner","doi":"10.1145/800031.808608","DOIUrl":"https://doi.org/10.1145/800031.808608","url":null,"abstract":"The term “graphics dynamics” is used in this paper to describe a capability which permits the application programmer to specify a relationship between various graphics input devices and aspects of the graphics output presentation. Subsequent use of the input devices results in continuous real-time changes to the picture. An experimental graphics system is described, in which a powerful programmer's interface to graphics dynamics was implemented. This interface appears suitable for use as an extension to any of the existing standards and standards proposals, including, CORE, GKS, and PHIGS.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122822623","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}
Shading is an important part of computer imagery, but shaders have been based on fixed models to which all surfaces must conform. As computer imagery becomes more sophisticated, surfaces have more complex shading characteristics and thus require a less rigid shading model. This paper presents a flexible tree-structured shading model that can represent a wide range of shading characteristics. The model provides an easy means for specifying complex shading characteristics. It is also efficient because it can tailor the shading calculations to each type of surface.
{"title":"Shade trees","authors":"R. L. Cook","doi":"10.1145/800031.808602","DOIUrl":"https://doi.org/10.1145/800031.808602","url":null,"abstract":"Shading is an important part of computer imagery, but shaders have been based on fixed models to which all surfaces must conform. As computer imagery becomes more sophisticated, surfaces have more complex shading characteristics and thus require a less rigid shading model. This paper presents a flexible tree-structured shading model that can represent a wide range of shading characteristics. The model provides an easy means for specifying complex shading characteristics. It is also efficient because it can tailor the shading calculations to each type of surface.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123047555","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 flexible interface to computing environments can be provided by gestural input. We describe a prototype system that recognizes some types of single-finger gestures and uses these gestures to manipulate displayed objects. An experimental gesture input device yields information about single finger gestures in terms of position, pressure, and shear forces on a screen. The gestures are classified by a “gesture parser” and used to control actions in a fingerpainting program, an interactive computing system designed for young children, and an interactive digital logic simulation.
{"title":"Manipulating simulated objects with real-world gestures using a force and position sensitive screen","authors":"M. Minsky","doi":"10.1145/800031.808598","DOIUrl":"https://doi.org/10.1145/800031.808598","url":null,"abstract":"A flexible interface to computing environments can be provided by gestural input. We describe a prototype system that recognizes some types of single-finger gestures and uses these gestures to manipulate displayed objects. An experimental gesture input device yields information about single finger gestures in terms of position, pressure, and shear forces on a screen. The gestures are classified by a “gesture parser” and used to control actions in a fingerpainting program, an interactive computing system designed for young children, and an interactive digital logic simulation.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129393282","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}
Clinton N. Waggoner, C. Tucker, Christopher J. Nelson
NOVA*GKS is an implementation of the Draft International Standard Graphical Kernel System (GKS), built using a distributed architecture. The specifications for GKS present an implementor with many design tradeoff decisions. The implementors of NOVA*GKS have analyzed those tradeoffs and created a distributed design which allows users of the package to design applications which can perform efficiently on many different graphics hardware configurations.
{"title":"Nova*gks, a distributed implementation of the Graphical Kernel System","authors":"Clinton N. Waggoner, C. Tucker, Christopher J. Nelson","doi":"10.1145/800031.808610","DOIUrl":"https://doi.org/10.1145/800031.808610","url":null,"abstract":"NOVA*GKS is an implementation of the Draft International Standard Graphical Kernel System (GKS), built using a distributed architecture. The specifications for GKS present an implementor with many design tradeoff decisions. The implementors of NOVA*GKS have analyzed those tradeoffs and created a distributed design which allows users of the package to design applications which can perform efficiently on many different graphics hardware configurations.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"242 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132573165","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}
Haruo Niimi, Y. Imai, Masayoshi Murakami, S. Tomita, H. Hagiwara
This paper describes the hardware architecture and the employed algorithm of a parallel processor system for three-dimensional color graphics. The design goal of the system is to generate realistic images of three-dimensional environments on a raster-scan video display in real-time. In order to achieve this goal, the system is constructed as a two-level hierarchical multi-processor system which is particularly suited to incorporate scan-line algorithm for hidden surface elimination. The system consists of several Scan-Line Processors (SLPs), each of which controls several slave PiXel Processors (PXPs). The SLP prepares the specific data structure relevant to each scan line, while the PXP manipulates every pixel data in its own territory. Internal hardware structures of the SLP and the PXP are quite different, being designed for their dedicated tasks. This system architecture can easily execute scan-line algorithm in parallel by partitioning the entire image space and allotting one processor element to each partition. The specific partition scheme and some new data structures are introduced to exploit as much parallelism as possible. In addition, the scan-line algorithm is extended to include smooth-shading and anti-aliasing with the aim of rendering more realistic images. These two operations are performed on a per-scan-line basis so as to preserve scan-line and span coherence. Performance estimation of the system shows that a typical system consisting of 8 SLPs and 8×8 PXPs can generate, in every 1/15th of a second, the shadowed image of a three-dimensional scene containing about 200 polygons.
{"title":"A parallel processor system for three-dimensional color graphics","authors":"Haruo Niimi, Y. Imai, Masayoshi Murakami, S. Tomita, H. Hagiwara","doi":"10.1145/800031.808580","DOIUrl":"https://doi.org/10.1145/800031.808580","url":null,"abstract":"This paper describes the hardware architecture and the employed algorithm of a parallel processor system for three-dimensional color graphics. The design goal of the system is to generate realistic images of three-dimensional environments on a raster-scan video display in real-time. In order to achieve this goal, the system is constructed as a two-level hierarchical multi-processor system which is particularly suited to incorporate scan-line algorithm for hidden surface elimination. The system consists of several Scan-Line Processors (SLPs), each of which controls several slave PiXel Processors (PXPs). The SLP prepares the specific data structure relevant to each scan line, while the PXP manipulates every pixel data in its own territory. Internal hardware structures of the SLP and the PXP are quite different, being designed for their dedicated tasks. This system architecture can easily execute scan-line algorithm in parallel by partitioning the entire image space and allotting one processor element to each partition. The specific partition scheme and some new data structures are introduced to exploit as much parallelism as possible. In addition, the scan-line algorithm is extended to include smooth-shading and anti-aliasing with the aim of rendering more realistic images. These two operations are performed on a per-scan-line basis so as to preserve scan-line and span coherence. Performance estimation of the system shows that a typical system consisting of 8 SLPs and 8×8 PXPs can generate, in every 1/15th of a second, the shadowed image of a three-dimensional scene containing about 200 polygons.","PeriodicalId":113183,"journal":{"name":"Proceedings of the 11th annual conference on Computer graphics and interactive techniques","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116900468","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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