ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00626.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractSome theoretical extensions are brought to Koparkar and Mudur's method which deals with a polygonal approximation of parametric surfaces using potential extrema. The proposed extensions allow the determination of both the existence and the equation of a curve solution of potential extrema. Solutions are given to solve the crack problem and to avoid the artificats due to an inexact ray‐surface intersection point near the silhouette or on the higher curvature regions. Moreover, two methods of ray tracing surfaces are propose

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00627.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe modelling clip as proposed for example in PHIGS is mathematically analyzed and a method to perform it is proposed. The method has the particular edvantage of avoiding all possible singularities appearing in the course of a projective transformation. Additionally, further optimizations in the implementation of the whole output pipeline are proposed.

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00628.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00629.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA survey on computer animation is presented with three specific goals:•To clarify what people understand by computer animation.•To separate the different aspects of computer animation and underline its main problems.•To present the different solutions given to these problems.Several classifications for computer animation systems are first made attending to different criteria. The report is subsequently divided into two basic sections according to the historical classification of computer animation systems: computer‐assisted animation, where traditional animation is just helped by the use of computers, and modelled animation where the use of computers is essential in different aspects of the animation process. Special emphasis is placed on motion specification and generation.Finally, special attention is paid to human body animation because of the great interest of this specific field of computer animation and the peculiarity of its problems.Aspects of hardware aspects and postprocessing has just been taken into account in the classification section but have not been

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00630.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractAn object oriented approach to the real‐time rendering of raster images is described. The architecture is based on a set of object processors arranged in a pipeline. These object processors scan convert the objects in the scene and interpolate depth and normal vectors across the objects. Hidden surface elimination is distributed along the pipeline. The structure of the object processors and of the algorithms employed are described in detail.Computing Reviews Classification: C. 1.2, C.3, 1.3

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00631.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA model for the handling of resources used in interactive programs, with emphasis on the input device part, is developed. Its connection to the I/O pair model and its usage in the dialogue cell system is described.The definition and properties of basic dialogue cells are given. A method for constructing a basic cell library is presented. A number of results from the application of the resource model on a basic cell library is shown.

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00632.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractTraditional interactive drawing programs adopt a bottom‐up approach, allowing the user to construct a picture by the use of discrete tools, for example, lines, circles, rectangles, and so on. This paper presents a different approach, which allows users to construct graphical objects by stretching and cutting existing objects. The representation is simply implemented, based on a ring of cubic Bezier curves, and use of the de Casteljau algorith

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00633.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractWe demonstrate how botharea coherenceandparallelismcan be exploited in order to speed up rendering operations on a SIMD square array of processors. Our algorithms take advantage of the method of differences, in order to incrementally compute the values of a linear polynomial function at discrete intervals and thus implement area rendering operations efficiently. We discuss how filling of convex polygons, hidden surface elimination and smooth shading can be implemented on anN × Nprocessor array that supports planar arithmetic, that is, arithmetic operations performed onN × Nmatrices in parallel for all matrix elements. A major attraction of the method we present is that it is based on a SIMD processor array; such machines are now recognised as highly general purpose given the wide range of applications successfully implemented on the

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00634.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA simple algorithm that improves colour shaded images is presented. The algorithm does not trade spatial resolution for intensity resolution. The basic technique, based on random thresholding modulated by a pseudo‐random number generator of uniform distribution, is introduced to render halftone images on bi‐level displays. A generalization of the technique is done for displays with multiple bi‐per‐colour components. An obvious advantage of the algorithm presented over other reported methods is its simplicity. Pictures are included to show results of the al

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1988.tb00635.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY