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Hidden surface removal in polyhedral cross-sections
Literature reviews Electronic design automation Shirai, K and Takezawa, T 'Expert system for designing digital signal processor architectures' Microprocessors Microsyst. Vol 12 No 2 (1988) pp 83 91 A design system for DSP devices has been developed that can synthesize a data path from the high-level specification of a DSP algorithm. A block diagram is displayed as a user interface.
Wolf, W H, Mathews, R G and Dutton, R W 'Algorithms for optimizing, twodimensional symbolic layout compaction' IEEETrans. CAD Integ. Circuits Syst. Vol 7 No 4 (1988) pp 451 466 A set of algorithms, collectively called Supercompaction, are described. They analyse a 2D layout during compaction to determine which changes will most improve the design. The algorithms minimize a 1D objective function (pitch) by moving objects in the layout in 2D till a locally minimal value is reached. The iterations needed to reach this value are shown experimentally to be few. It is atso shown that supercompacted layouts are smaller in pitch and area than those produced by existing 1D algorithms.
Nahar, S and Sahni, S 'Fast algorithm for polygon decomposition' IEEETrans. CAD Integ. Circuits Syst. Vol 7 No 4 (1988) pp 473 483 An algorithm is described that can decompose rectilinear hole-free polygons into a minimum number of rectangles that are required to be disjoint. This algorithm uses horizontal cuts only. It has been programmed in Pascal on an Apollo DN 320 workstation. Experimental results using VLSI mask data indicate that the algorithm is faster than the plane sweep algorithm.
Nye, W, Riley, D C, SangiovanniVincentelli, A and Tits, A L 'DELIGHT. SPICE: an optimization based system for the design of integrated circuits' IEEE Trans. CAD Integ. Circuits Syst. Vol 7 No 4 (1988) pp 501 DELIGHT.SPACE is formed from the union of the DELIGHT interactive optimization-based CAD system and the SPICE circuit analysis program. The SPICE program used was enhanced to perform DC AC and transient sensitivity computation. Industrial anavolume 20 number 7 september 1988
togue and digital circuits were redesigned using DELIGHT.SPACE and yielded substantial improvements in circuit performance.
network is used to implement a geometric reasoner for a computer vision program.
Hicks, P J, Cottrell, R A and York,
Gossard, D C, Zuffante, R P and Sakurai, H 'Representing dimensions,
T A 'Overview of semicustom IC design' Microprocessors Microsyst. Vol 12 No 5 (1988) pp 245-259
tolerances, and features in MCAE systems' IEEE Comput. Graph. Appl. Vol 8 No 2 pp 51-59
Semicustom IC design is introduced. A range of CAD tools necessary in the design process are discussed. Descriptions of gate arrays cell-based systems and programmable logic devices are given. Typical routes to fabrication are described and costs are compared for each approach.
A method for explicitly representing dimensions, tolerances, and geometric features in solid models is given. It combines CSG and boundary representations in a graph structure called an object graph. It can translate changes in dimensional values into corresponding changes in geometry and topology. A prototype interactive polyhedral modeller was built, based on this representation.
Braun, D, Burns,J, Romeo, F,SangiovanniVincentelli, A, Mayaram, K, Devadas, S and Tony, H K 'Techniques for multilayer channel routing' IEEE Trans. Comput.Aided Des. Integ. Circuits Syst.Vol 7 No 6 (1988) pp 698 712 New techniques for routing general multilayer channels are introduced, they have been implemented in a multilayer channel router called Chameleon. Chameleon consists of 2 stages: a partitioner and a detailed router. The partitioner subdivides the problem into two- and three-layer subproblems to minimize the global channel area. The detailed router then implements the corrections.
Egyed, P 'Hidden surface removal in polyhedral cross-sections' The Visual Comput. Vol 3 No 6 (1988) pp 329-343 One approach to the problem of eliminating hidden surfaces involves assigning depth priority numbers to the faces of a scene. The faces are then displayed using the priority ordering. A tree-based formalism for describing priority orderings is introduced. This algorithm requires O(nlogn) time if t (the minimum decomposition factor of the scene)= 1 and O(tnlogn + nlognlogm) if t > 1 where n and m are respectively the number of faces and polyhedra in the scene.
Graphical techniques Avis, D, Batlychara, B K and Imai, H Phillips, T H and Rosenfeld, A 'Decomposition of 3D objects into compact subobjects by analysis of cross-sections' Image Vision Comput. Vol 6 No I (1988) pp 33 51 A method of decomposing 3D objects, defined by binary arrays, into compact subobjects by analysing the stack of 2D arrays containing cross-sections of the objects is presented.
Fisher, R B and Orr, M L 'Solving geometric constraints in a parallel network' Image Vision Comput. Vol 6 No 2 (1988) pp 100-106 A network implementation of the SUP-INF method for solving sets of inequalities is described. Iteration is allowed in the network and this improves the competence of the method when dealing with nonlinear constraints. The
'Computing the volume of the union of spheres' The Visual Comput. Vol 3 No 6 (1988) pp 323-328 An O(n 2) exact algorithm for computing the volume of a set of n spheres in space is presented.
Dean, J A, Lingas, A and Sack, J-R 'Recognizing polygons, or how to spy' The Visual Comput. Vol 3 No 6 (1988) pp 344 355 A new class of polygons - pseudostarshaped - is introduced that unifies and generalizes three traditional computational geometry polygon classes i.e. convex star-shaped and monotone. Algorithms are provided that test whether a polygon is pseudostar-shaped in linear time and that construct all regions from which the polygon is pseudostar-shaped in quadratic time. 423
Wolf, W H, Mathews, R G and Dutton, R W 'Algorithms for optimizing, twodimensional symbolic layout compaction' IEEETrans. CAD Integ. Circuits Syst. Vol 7 No 4 (1988) pp 451 466 A set of algorithms, collectively called Supercompaction, are described. They analyse a 2D layout during compaction to determine which changes will most improve the design. The algorithms minimize a 1D objective function (pitch) by moving objects in the layout in 2D till a locally minimal value is reached. The iterations needed to reach this value are shown experimentally to be few. It is atso shown that supercompacted layouts are smaller in pitch and area than those produced by existing 1D algorithms.
Nahar, S and Sahni, S 'Fast algorithm for polygon decomposition' IEEETrans. CAD Integ. Circuits Syst. Vol 7 No 4 (1988) pp 473 483 An algorithm is described that can decompose rectilinear hole-free polygons into a minimum number of rectangles that are required to be disjoint. This algorithm uses horizontal cuts only. It has been programmed in Pascal on an Apollo DN 320 workstation. Experimental results using VLSI mask data indicate that the algorithm is faster than the plane sweep algorithm.
Nye, W, Riley, D C, SangiovanniVincentelli, A and Tits, A L 'DELIGHT. SPICE: an optimization based system for the design of integrated circuits' IEEE Trans. CAD Integ. Circuits Syst. Vol 7 No 4 (1988) pp 501 DELIGHT.SPACE is formed from the union of the DELIGHT interactive optimization-based CAD system and the SPICE circuit analysis program. The SPICE program used was enhanced to perform DC AC and transient sensitivity computation. Industrial anavolume 20 number 7 september 1988
togue and digital circuits were redesigned using DELIGHT.SPACE and yielded substantial improvements in circuit performance.
network is used to implement a geometric reasoner for a computer vision program.
Hicks, P J, Cottrell, R A and York,
Gossard, D C, Zuffante, R P and Sakurai, H 'Representing dimensions,
T A 'Overview of semicustom IC design' Microprocessors Microsyst. Vol 12 No 5 (1988) pp 245-259
tolerances, and features in MCAE systems' IEEE Comput. Graph. Appl. Vol 8 No 2 pp 51-59
Semicustom IC design is introduced. A range of CAD tools necessary in the design process are discussed. Descriptions of gate arrays cell-based systems and programmable logic devices are given. Typical routes to fabrication are described and costs are compared for each approach.
A method for explicitly representing dimensions, tolerances, and geometric features in solid models is given. It combines CSG and boundary representations in a graph structure called an object graph. It can translate changes in dimensional values into corresponding changes in geometry and topology. A prototype interactive polyhedral modeller was built, based on this representation.
Braun, D, Burns,J, Romeo, F,SangiovanniVincentelli, A, Mayaram, K, Devadas, S and Tony, H K 'Techniques for multilayer channel routing' IEEE Trans. Comput.Aided Des. Integ. Circuits Syst.Vol 7 No 6 (1988) pp 698 712 New techniques for routing general multilayer channels are introduced, they have been implemented in a multilayer channel router called Chameleon. Chameleon consists of 2 stages: a partitioner and a detailed router. The partitioner subdivides the problem into two- and three-layer subproblems to minimize the global channel area. The detailed router then implements the corrections.
Egyed, P 'Hidden surface removal in polyhedral cross-sections' The Visual Comput. Vol 3 No 6 (1988) pp 329-343 One approach to the problem of eliminating hidden surfaces involves assigning depth priority numbers to the faces of a scene. The faces are then displayed using the priority ordering. A tree-based formalism for describing priority orderings is introduced. This algorithm requires O(nlogn) time if t (the minimum decomposition factor of the scene)= 1 and O(tnlogn + nlognlogm) if t > 1 where n and m are respectively the number of faces and polyhedra in the scene.
Graphical techniques Avis, D, Batlychara, B K and Imai, H Phillips, T H and Rosenfeld, A 'Decomposition of 3D objects into compact subobjects by analysis of cross-sections' Image Vision Comput. Vol 6 No I (1988) pp 33 51 A method of decomposing 3D objects, defined by binary arrays, into compact subobjects by analysing the stack of 2D arrays containing cross-sections of the objects is presented.
Fisher, R B and Orr, M L 'Solving geometric constraints in a parallel network' Image Vision Comput. Vol 6 No 2 (1988) pp 100-106 A network implementation of the SUP-INF method for solving sets of inequalities is described. Iteration is allowed in the network and this improves the competence of the method when dealing with nonlinear constraints. The
'Computing the volume of the union of spheres' The Visual Comput. Vol 3 No 6 (1988) pp 323-328 An O(n 2) exact algorithm for computing the volume of a set of n spheres in space is presented.
Dean, J A, Lingas, A and Sack, J-R 'Recognizing polygons, or how to spy' The Visual Comput. Vol 3 No 6 (1988) pp 344 355 A new class of polygons - pseudostarshaped - is introduced that unifies and generalizes three traditional computational geometry polygon classes i.e. convex star-shaped and monotone. Algorithms are provided that test whether a polygon is pseudostar-shaped in linear time and that construct all regions from which the polygon is pseudostar-shaped in quadratic time. 423