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Mechanism synthesis using the workstation environment
Literature reviews Xie, S-E and Calvert, T W 'CSGEESI: a new solid representation scheme and a conversion expert system' IEEE
Trans. Pattern Analysis Mach. Intell. Vol 10 No 2 (1988) pp 221 234 A representation scheme is presented that can describe 3D mechanical parts and structured bodies formed from planes and quadric faces. The method combines features of constructive solid geometry and an extension of the enhanced spherical image representation (ESI). The body model is divided into two levels: the higher level corresponds to a restricted CSG tree containing structural information on how the subparts form the body; the lower level contains the geometric information for those subparts using the extended ESI representation. An expert system written in C-Prolog on a VAX 11/750 is described that can convert boundary representation models into the CSG-EESI representation.
EIGindy, H and Goodrich, M 'Parallel algorithms for shortest path problems in polygons' The Visual Comput. Vol 3 No 6 (1988) pp 371-378 Two variations of the Euclidean shortest path problem inside a simple polygon are studied. First, the Interior Shortest Path (ISP): find the path with the shortest Euclidean distance between two points S and D inside an n-vertex polygon P; second, the All Interior Shortest Paths (ALSP) problem: compute the shortest path tree between a single point s and each vertex of P. The algorithms to solve these problems are based on the 'divide and conquer' paradigm.
Dehne, F 'Solving visibility and separability problems on a mesh of processors' The Visual Comput. Vol 3 No 6 (1988) pp 356 370 Parallel algorithms for the 'mesh of processors' architecture are presented to solve visibility and related separability problems for a set of simple polygons in the plane.
Barris, W C, Kota, S, Riley, D R and Erdman, A G 'Mechanism synthesis using the workstation environment' IEEE Comput. Graph. Appl. Vol 8 No 2 pp 39-50 Previously, the adoption of mechanism synthesis packages has been limited by 424
their poor user inteffa(:es. New ( apabilities arising out of improved hardware and operating systems su(h as (olour, rnultiple windows, dynami( menuing and animation are dis( ussed with regard to their impact on the mechanism synthesis process. Specific examples of the use of colour raster workstations to provide user-friendly general purpose user interface tools are presented. The impact of the advanced workstation environment on CAD is assessed.
Flaquer, I and Rodil, l L 'B~oleal! ()perati()n> based ()[~ thu tflana~ p(fly hedra[ representation ( ,~mput. & (;laph Vol 12 No 1 (1988i pl ) ~) 64 Boolean operatiorls are not performed on (urved objects bL,t between their planar polyhedral representations i.u. Boolean ol)erations are only performed between objects bounded by flat fa(es (fa(ets). The resultant objects are then used as the starting [)(tint for obtaining t h e ( u r v e d on(~s.
Paukowitsch, P 'Fundamental ideas for computer-supported descriptive geometry' Compul. & Graph Vol 12 No 1 (1988) pp 3 14 Problems of descriptive geometry are solved using an axonometric method for the uniform realisation of parallel and central projection.
Schaal, H 'Computer graphical treatments of perspective pictures' Compul. & Graph. Vol 12 No 1 (1988) pp 15 31 Two engravings by Durer are examined for their use of the perspective view. Explicit formulas are derived for describing the difference between an object and its representation. These are applied to an aerial picture as well as Durer's engravings to demonstrate their application.
Ajjanagadde, V G and Patnaik, L M
Comput. & Graph. Vol 12 No 1 (1988) pp 71 74 A systolic architecture for hiddensurface removal is proposed. Sign details are discussed and simulation results presented.
Parker J R 'Extracting vectors from raster images' Comput. & Graph. Vo112 No 1 (1988) pp 75-79 Raster to vector conversion consists of two steps: identification and enhancement of regions of interest; then extraction of lines as vectors where they satisfy given conditions. The latter operation is discussed.
Nagendra, I V and Gujar, U G '3D objects from 2D orthographic views: a survey' Comput. & Graph. Vol 12 No 1 (1988) pp 111 114 Papers published between 1973- 1984 are reviewed and relevant features of algorithms are tabulated.
Walker, M, Lo, R S and Cheng, S F 'Hidden line detection in polytree representations' C()mf)ut. & (;raph. Vol 12 No 1 (1988) pl ) 65 69 An algorithm is presented for creating wireframe orthographic or proje(tive display of an obie(t encoded in a polytree representation. The algorithm works directly from the representation without prior ~onversion to another representation tormat.
Woodwark, J R 'Eliminating redundant primitives from set-theoretic solid models by a consideration of constituents' IEE[Conrpul. Graph. & Appl. Vol 8 No ~, (1988) pp 38 47 A technique that allows eliminations of redundant from set-theoretic solid proposed. A method of tation is outlined.
alternative primitives models is implemen-
garnet, H and and Webber,
R E
'Hierarchical data structures and algorithms for computer graphics: part I' IEEE Comput. Graph. & Appl. Vol 8 No (1988) pp 48 -68 This is the first of a two part overview of the use of hierarchical data structures and algorithms in graphics. Part I focuses on fundamentals, including quadtrees and octrees.
Turner, I U 'Accurate solid modelling using polyhedral approximations' IEEE Comput. Graph. & AppL Vol 8 No 3 (1988) pp 14-28 A method for calculating accurate boundary representations of solid models is presented. The method employs a pair of bounding polyhedral approximations to enclose the boundary of each object.
computer-aided design
Trans. Pattern Analysis Mach. Intell. Vol 10 No 2 (1988) pp 221 234 A representation scheme is presented that can describe 3D mechanical parts and structured bodies formed from planes and quadric faces. The method combines features of constructive solid geometry and an extension of the enhanced spherical image representation (ESI). The body model is divided into two levels: the higher level corresponds to a restricted CSG tree containing structural information on how the subparts form the body; the lower level contains the geometric information for those subparts using the extended ESI representation. An expert system written in C-Prolog on a VAX 11/750 is described that can convert boundary representation models into the CSG-EESI representation.
EIGindy, H and Goodrich, M 'Parallel algorithms for shortest path problems in polygons' The Visual Comput. Vol 3 No 6 (1988) pp 371-378 Two variations of the Euclidean shortest path problem inside a simple polygon are studied. First, the Interior Shortest Path (ISP): find the path with the shortest Euclidean distance between two points S and D inside an n-vertex polygon P; second, the All Interior Shortest Paths (ALSP) problem: compute the shortest path tree between a single point s and each vertex of P. The algorithms to solve these problems are based on the 'divide and conquer' paradigm.
Dehne, F 'Solving visibility and separability problems on a mesh of processors' The Visual Comput. Vol 3 No 6 (1988) pp 356 370 Parallel algorithms for the 'mesh of processors' architecture are presented to solve visibility and related separability problems for a set of simple polygons in the plane.
Barris, W C, Kota, S, Riley, D R and Erdman, A G 'Mechanism synthesis using the workstation environment' IEEE Comput. Graph. Appl. Vol 8 No 2 pp 39-50 Previously, the adoption of mechanism synthesis packages has been limited by 424
their poor user inteffa(:es. New ( apabilities arising out of improved hardware and operating systems su(h as (olour, rnultiple windows, dynami( menuing and animation are dis( ussed with regard to their impact on the mechanism synthesis process. Specific examples of the use of colour raster workstations to provide user-friendly general purpose user interface tools are presented. The impact of the advanced workstation environment on CAD is assessed.
Flaquer, I and Rodil, l L 'B~oleal! ()perati()n> based ()[~ thu tflana~ p(fly hedra[ representation ( ,~mput. & (;laph Vol 12 No 1 (1988i pl ) ~) 64 Boolean operatiorls are not performed on (urved objects bL,t between their planar polyhedral representations i.u. Boolean ol)erations are only performed between objects bounded by flat fa(es (fa(ets). The resultant objects are then used as the starting [)(tint for obtaining t h e ( u r v e d on(~s.
Paukowitsch, P 'Fundamental ideas for computer-supported descriptive geometry' Compul. & Graph Vol 12 No 1 (1988) pp 3 14 Problems of descriptive geometry are solved using an axonometric method for the uniform realisation of parallel and central projection.
Schaal, H 'Computer graphical treatments of perspective pictures' Compul. & Graph. Vol 12 No 1 (1988) pp 15 31 Two engravings by Durer are examined for their use of the perspective view. Explicit formulas are derived for describing the difference between an object and its representation. These are applied to an aerial picture as well as Durer's engravings to demonstrate their application.
Ajjanagadde, V G and Patnaik, L M
Comput. & Graph. Vol 12 No 1 (1988) pp 71 74 A systolic architecture for hiddensurface removal is proposed. Sign details are discussed and simulation results presented.
Parker J R 'Extracting vectors from raster images' Comput. & Graph. Vo112 No 1 (1988) pp 75-79 Raster to vector conversion consists of two steps: identification and enhancement of regions of interest; then extraction of lines as vectors where they satisfy given conditions. The latter operation is discussed.
Nagendra, I V and Gujar, U G '3D objects from 2D orthographic views: a survey' Comput. & Graph. Vol 12 No 1 (1988) pp 111 114 Papers published between 1973- 1984 are reviewed and relevant features of algorithms are tabulated.
Walker, M, Lo, R S and Cheng, S F 'Hidden line detection in polytree representations' C()mf)ut. & (;raph. Vol 12 No 1 (1988) pl ) 65 69 An algorithm is presented for creating wireframe orthographic or proje(tive display of an obie(t encoded in a polytree representation. The algorithm works directly from the representation without prior ~onversion to another representation tormat.
Woodwark, J R 'Eliminating redundant primitives from set-theoretic solid models by a consideration of constituents' IEE[Conrpul. Graph. & Appl. Vol 8 No ~, (1988) pp 38 47 A technique that allows eliminations of redundant from set-theoretic solid proposed. A method of tation is outlined.
alternative primitives models is implemen-
garnet, H and and Webber,
R E
'Hierarchical data structures and algorithms for computer graphics: part I' IEEE Comput. Graph. & Appl. Vol 8 No (1988) pp 48 -68 This is the first of a two part overview of the use of hierarchical data structures and algorithms in graphics. Part I focuses on fundamentals, including quadtrees and octrees.
Turner, I U 'Accurate solid modelling using polyhedral approximations' IEEE Comput. Graph. & AppL Vol 8 No 3 (1988) pp 14-28 A method for calculating accurate boundary representations of solid models is presented. The method employs a pair of bounding polyhedral approximations to enclose the boundary of each object.
computer-aided design