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Eurographics '88
Conferencesand exhibitions Eurographics '88 C o m p u t e r G r a p h i c s Conference and Exhibition ( 1 2 - 1 6 S e p t e m b e r 1988, Nice, France) Eurographics '88 was the ninth in a series of annual conferences run by the European Association for Computer Graphics. It attracted 94 papers of which 41 were selected for presentation. A further three papers were invited and there were also four panel sessions, an audiovisual programme and a number of short applications papers. Only the discussion sessions are described here.
INTELLIGENT CAD SYSTEMS The panel on 'intelligent CAD systems' included Paul ten Hagen, Paul Veerkamp, Tetsuo Tomiyama and Tapio Takala, each of whom gave a brief overview of part of the proceedings of the Second Euroo graphics Workshop on ICAD. The ensuing discussion made it plain that ICAD is still emerging as a technology; there were strong disagreements as to emphasis and even definition. Tomiyama described the power of the object-oriented paradigm and discussed some examples (IDDL, Oar and Mole). Veerkamp looked at what designers wanted from an ICAD system. They want an assistant that can interpret high level concepts and translate them into low level operations. Veerkamp discussed work that described the design process as a problem solving process, i.e. mapping function space onto attribute space. A rough model is honed during a long session of design to produce a specific description. This stepwise refinement has to be captured by an ICAD system. There was some discussion in the audience at this point as some felt that design was more of an ad hoc activity with the designer jumping from global concepts down to specific function detail and back out again. For this kind of design, a stepwise goal achieving approach would appear to be inappropriate. This argument
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was countered by Veerkamp pointing out that the designer remains in control of the systems and can choose an ad hoc approach if required, as the system only acts as an assistant not a director to the designer. Takala reported on three papers presented at the Workshop concerned with the design process. The three papers argued for different approaches to forming a plan (the design process): • goal driven • evolutionary • by example/explanation, using a framework This led Takala to ask three questions: • What kind of intelligence should an ICAD system have? (e.g. logical inference or associative deduction) • What role should representations play in the user interfaces? (e.g. exact or metaphorical) • What architecture should an ICAD system have? (e.g. where does the intelligence lie - in the interface or in the application?) Tomiyama took up the latter question and pointed out that though there have been many attempts to develop systems with a narrow band of application specific knowledge, these could not truly be described as ICAD systems, because when presented with a problem marginally outside their domain of expertise, these systems failed completely, whereas 'real' intelligence would have the ability to reason about the problem in the light this knowledge.
GRAPHICS STANDARDS The panel for the discussion of 'graphics standards - present and future' was chaired by Peter de Bono and included Jane Pink, Madeleine Sparks, David Arnold, Jurgen Bettels and Andre Ducrot. Thus the panel
represented all the working groups of ISO subcommittee 24 (graphics standards), de Bono first oulined the steps that a proposal has to go through to be adopted as an international standard and then described the functions of the five working groups that form the subcommittee. The challenge of SC24, as he saw it, was to complete GKS (Graphical Kernel System)and PHIGS (Programmers Hierarchical Interactive Graphics System) and then maintain them, and to develop a second generation of standards that would be more requirements-driven and more responsive to implementors' needs. Ducrot reported on the efforts of Working Group (WG) 1. Its brief is to look carefully at the users of graphics standards requirements and specify graphics techniques. There are study groups who are working on new work items such as windowing environments, application program interfaces (APIs) for imaging, and extensions to the CGM (static picture capture). Bettels, reporting on WG2, described its role as the standardization of functional specifications for APIs. PHIGS and GKS are complete, but a review of GKS is contemplated; this will be a conservative upgrade of GKS that removes some implementation dependencies, adds error reporting, window integration and some limited new functionality. An addition to PHIGS of basic rendering is also being considered and this wilt add new primitives for arbitrarily shaped curves and surfaces and allow specification of depth-cueing, direct lighting and shading. Arnold said that WG3 has various projects connected with the CGM (Computer Graphics Metafile) and CGI (Computer Graphics Interface) under way. The CGM is a published standard, but maintenance is ongoing. The CGI is a draft proposal
computer-aided design
Conferences and exhibitions and is awaiting a second round of comments. There are two CGM Addendums, one connected with static picture capture and one connected with 3D metafiles; both are being worked on. Sparks' group (WG4) is working on language bindings i.e. tying the functional description of a graphics standard to a programming language standard. Current activities are concerned with CGI, PHIGS and GKS standards and Fortran, Pascal, Ada and C. C is not yet standardized and the CGI has proved the most difficult standard to work with. WG4 is also looking at languages like Lisp, Algol and Mumps in terms of GKS. Pink reported on the activities of the validation, testing and registration WG5. The role of this group is to develop and maintain procedures for testing and validating the implementations of graphics standards. Without some means of testing for conformance, it would be possible for implementations to deviate from the standard and this would negate the whole aim and purpose of specifying standards in the first place. WG5 looks for ambiguities in standards that could eventually lead to differences in implementation. WG5 hopes to provide test suites/ services for implementors which could then be used to measure an implementation's conformance to the published standard. Comments from the audience to this session centred on two aspects. First, the impact of industry standards and this led onto the second point which was the length of time it took for ISO standards to be accepted. One question that was asked was should industry standards be regarded as competition or coexistent with ISO standards. Arnold felt that industry standards such as X-window do not have the lack of ambiguity required by a standard. Bettels felt that the industry standards fell within the scope of special study groups within SC24, so they are getting attention. He felt there was a need to examine current practice and incorporate it into formal standards, de Bono said that such
volume 21 number 2 march 1989
standards were competition because it was possible to buy them now and they appeared to provide simple solutions to complex problems. He felt that this showed the need for the ISO standards process to be requirements- rather than technology-driven. The final comment on this issue was that although ISO standards may lag a little behind the times, they are very well thought out. Discussion moved on to the amount of time needed to get a standard accepted. There was general agreement within the audience that the time taken currently was too long. The panel countered this by pointing to the procedures required by ISO and by the small numbers of people available to do the work. In particular it was suggested that European industry could do more to support the work of SC24 (US industry is fully involved). Ducrot felt that the amount of time needed to develop a standard should be recognized and that effort should be put into developing standards ahead of current practice. A suggestion was made that future standards should not take as long to develop as the current ones because there is now a strong foundation to be built on, whereas the initial standards had to be developed from scratch. de Bono pointed out that the fastest possible time to develop a standard was two years given the ISO constraints and procedures and that this did not allow time for amount of work, time off, ability to attend meetings etc. It was then suggested that standards functionality stabilizes quickly and therefore it should be possible to publish a version early on and then update like a software package. Arnold felt that this process would not provide solid unambiguous standards. SUPERCOMPUTER GRAPHICS This session, chaired by Professor Encarnacao, examined the impact of supercomputers on graphics. Mehl started the session off by describing the needs of super-
computers when faced with such compute-intensive tasks as simulation, realism and animation. Bruell (Support Manager, Stellar) then gave an overview of Stellar's technology and described its approach to integrated computation and graphics. Professor Strasser discussed future technologies for supercomputers. Randi Rost (Principal Engineer, Workstation Engineering Group, DEC) took a broader approach and looked at what the user might expect from supercomputers and what was missing. Rost identified two groups of users: applications developers and end-users, and the needs of these two groups are different. Applications developers want: • • • • •
stable hardware platforms stable software platforms integrated environment high-level tools (e.g. 3D toolkits) graphics and CPU performance
End users want • • • • •
performance ease-of-use rendering capacity modelling capabilities integrated environment
Rost felt that too much effort was being put into so-called 'glamour' areas of raw performance and rendering, but not enough to integrated environments, hardware/ software stability and modelling capabilities. These panel sessions give a flavour of the ongoing debate carried out throughout Eurographics '88, but do not reflect the full range of papers. There were several sessions concerning geometric modelling and also sessions on animation, hardware, stochastic modellin& interfaces and illumination models. There was also an interesting session describing six applications of graphics which included aerodynamics, chemical modelling and road and streetlighting modelling. The Proceedings of this conference will be published by Elsevier Science Publishers.
J. Hayes 123
INTELLIGENT CAD SYSTEMS The panel on 'intelligent CAD systems' included Paul ten Hagen, Paul Veerkamp, Tetsuo Tomiyama and Tapio Takala, each of whom gave a brief overview of part of the proceedings of the Second Euroo graphics Workshop on ICAD. The ensuing discussion made it plain that ICAD is still emerging as a technology; there were strong disagreements as to emphasis and even definition. Tomiyama described the power of the object-oriented paradigm and discussed some examples (IDDL, Oar and Mole). Veerkamp looked at what designers wanted from an ICAD system. They want an assistant that can interpret high level concepts and translate them into low level operations. Veerkamp discussed work that described the design process as a problem solving process, i.e. mapping function space onto attribute space. A rough model is honed during a long session of design to produce a specific description. This stepwise refinement has to be captured by an ICAD system. There was some discussion in the audience at this point as some felt that design was more of an ad hoc activity with the designer jumping from global concepts down to specific function detail and back out again. For this kind of design, a stepwise goal achieving approach would appear to be inappropriate. This argument
122
was countered by Veerkamp pointing out that the designer remains in control of the systems and can choose an ad hoc approach if required, as the system only acts as an assistant not a director to the designer. Takala reported on three papers presented at the Workshop concerned with the design process. The three papers argued for different approaches to forming a plan (the design process): • goal driven • evolutionary • by example/explanation, using a framework This led Takala to ask three questions: • What kind of intelligence should an ICAD system have? (e.g. logical inference or associative deduction) • What role should representations play in the user interfaces? (e.g. exact or metaphorical) • What architecture should an ICAD system have? (e.g. where does the intelligence lie - in the interface or in the application?) Tomiyama took up the latter question and pointed out that though there have been many attempts to develop systems with a narrow band of application specific knowledge, these could not truly be described as ICAD systems, because when presented with a problem marginally outside their domain of expertise, these systems failed completely, whereas 'real' intelligence would have the ability to reason about the problem in the light this knowledge.
GRAPHICS STANDARDS The panel for the discussion of 'graphics standards - present and future' was chaired by Peter de Bono and included Jane Pink, Madeleine Sparks, David Arnold, Jurgen Bettels and Andre Ducrot. Thus the panel
represented all the working groups of ISO subcommittee 24 (graphics standards), de Bono first oulined the steps that a proposal has to go through to be adopted as an international standard and then described the functions of the five working groups that form the subcommittee. The challenge of SC24, as he saw it, was to complete GKS (Graphical Kernel System)and PHIGS (Programmers Hierarchical Interactive Graphics System) and then maintain them, and to develop a second generation of standards that would be more requirements-driven and more responsive to implementors' needs. Ducrot reported on the efforts of Working Group (WG) 1. Its brief is to look carefully at the users of graphics standards requirements and specify graphics techniques. There are study groups who are working on new work items such as windowing environments, application program interfaces (APIs) for imaging, and extensions to the CGM (static picture capture). Bettels, reporting on WG2, described its role as the standardization of functional specifications for APIs. PHIGS and GKS are complete, but a review of GKS is contemplated; this will be a conservative upgrade of GKS that removes some implementation dependencies, adds error reporting, window integration and some limited new functionality. An addition to PHIGS of basic rendering is also being considered and this wilt add new primitives for arbitrarily shaped curves and surfaces and allow specification of depth-cueing, direct lighting and shading. Arnold said that WG3 has various projects connected with the CGM (Computer Graphics Metafile) and CGI (Computer Graphics Interface) under way. The CGM is a published standard, but maintenance is ongoing. The CGI is a draft proposal
computer-aided design
Conferences and exhibitions and is awaiting a second round of comments. There are two CGM Addendums, one connected with static picture capture and one connected with 3D metafiles; both are being worked on. Sparks' group (WG4) is working on language bindings i.e. tying the functional description of a graphics standard to a programming language standard. Current activities are concerned with CGI, PHIGS and GKS standards and Fortran, Pascal, Ada and C. C is not yet standardized and the CGI has proved the most difficult standard to work with. WG4 is also looking at languages like Lisp, Algol and Mumps in terms of GKS. Pink reported on the activities of the validation, testing and registration WG5. The role of this group is to develop and maintain procedures for testing and validating the implementations of graphics standards. Without some means of testing for conformance, it would be possible for implementations to deviate from the standard and this would negate the whole aim and purpose of specifying standards in the first place. WG5 looks for ambiguities in standards that could eventually lead to differences in implementation. WG5 hopes to provide test suites/ services for implementors which could then be used to measure an implementation's conformance to the published standard. Comments from the audience to this session centred on two aspects. First, the impact of industry standards and this led onto the second point which was the length of time it took for ISO standards to be accepted. One question that was asked was should industry standards be regarded as competition or coexistent with ISO standards. Arnold felt that industry standards such as X-window do not have the lack of ambiguity required by a standard. Bettels felt that the industry standards fell within the scope of special study groups within SC24, so they are getting attention. He felt there was a need to examine current practice and incorporate it into formal standards, de Bono said that such
volume 21 number 2 march 1989
standards were competition because it was possible to buy them now and they appeared to provide simple solutions to complex problems. He felt that this showed the need for the ISO standards process to be requirements- rather than technology-driven. The final comment on this issue was that although ISO standards may lag a little behind the times, they are very well thought out. Discussion moved on to the amount of time needed to get a standard accepted. There was general agreement within the audience that the time taken currently was too long. The panel countered this by pointing to the procedures required by ISO and by the small numbers of people available to do the work. In particular it was suggested that European industry could do more to support the work of SC24 (US industry is fully involved). Ducrot felt that the amount of time needed to develop a standard should be recognized and that effort should be put into developing standards ahead of current practice. A suggestion was made that future standards should not take as long to develop as the current ones because there is now a strong foundation to be built on, whereas the initial standards had to be developed from scratch. de Bono pointed out that the fastest possible time to develop a standard was two years given the ISO constraints and procedures and that this did not allow time for amount of work, time off, ability to attend meetings etc. It was then suggested that standards functionality stabilizes quickly and therefore it should be possible to publish a version early on and then update like a software package. Arnold felt that this process would not provide solid unambiguous standards. SUPERCOMPUTER GRAPHICS This session, chaired by Professor Encarnacao, examined the impact of supercomputers on graphics. Mehl started the session off by describing the needs of super-
computers when faced with such compute-intensive tasks as simulation, realism and animation. Bruell (Support Manager, Stellar) then gave an overview of Stellar's technology and described its approach to integrated computation and graphics. Professor Strasser discussed future technologies for supercomputers. Randi Rost (Principal Engineer, Workstation Engineering Group, DEC) took a broader approach and looked at what the user might expect from supercomputers and what was missing. Rost identified two groups of users: applications developers and end-users, and the needs of these two groups are different. Applications developers want: • • • • •
stable hardware platforms stable software platforms integrated environment high-level tools (e.g. 3D toolkits) graphics and CPU performance
End users want • • • • •
performance ease-of-use rendering capacity modelling capabilities integrated environment
Rost felt that too much effort was being put into so-called 'glamour' areas of raw performance and rendering, but not enough to integrated environments, hardware/ software stability and modelling capabilities. These panel sessions give a flavour of the ongoing debate carried out throughout Eurographics '88, but do not reflect the full range of papers. There were several sessions concerning geometric modelling and also sessions on animation, hardware, stochastic modellin& interfaces and illumination models. There was also an interesting session describing six applications of graphics which included aerodynamics, chemical modelling and road and streetlighting modelling. The Proceedings of this conference will be published by Elsevier Science Publishers.
J. Hayes 123