112 research outputs found
The Computer Graphics Scene in the United States
We briefly survey the major thrusts of computer graphics activities, examining trends and topics rather than offering a comprehensive survey of all that is happening. The directions of professional activities, hardware, software, and algorithms are outlined. Within hardware we examine workstations, personal graphics systems, high performance systems, and low level VLSI chips; within software, standards and interactive system design; within algorithms, visible surface rendering and shading, three-dimensional modeling techniques, and animation.
Note: This paper was presented at Eurographics\u2784 in Copenhagen, Denmark
Assessment of classical database models for representing solids
Solid modeling is being explored as a method of representing three dimensional parts for mechanical design and manufacturing. This work analyzes the data storage requirements of the Boundary Representation and Constructive Solid Geometry methods of representing solid models. The ability of the database models (Hierarchical, Network, and Relational) to support solid modeling needs is evaluated. The goal is to determine the database model(s) best suited to store and manage the graphical data for solid model representat ions . Background information about mechanical engineering, graphics, and database models is presented. Entity-Relationship diagrams are used to define data requ irements
Algorithm to layout (ATL) systems for VLSI design
PhD ThesisThe complexities involved in custom VLSI design together with the
failure of CAD techniques to keep pace with advances in the fabrication
technology have resulted in a design bottleneck. Powerful tools are
required to exploit the processing potential offered by the densities now
available. Describing a system in a high level algorithmic notation
makes writing, understanding, modification, and verification of a design
description easier. It also removes some of the emphasis on the physical
issues of VLSI design, and focus attention on formulating a correct and
well structured design. This thesis examines how current trends in CAD
techniques might influence the evolution of advanced Algorithm To Layout
(ATL) systems. The envisaged features of an example system are
specified. Particular attention is given to the implementation of one
its features COPTS (Compilation Of Occam Programs To Schematics).
COPTS is capable of generating schematic diagrams from which an
actual layout can be derived. It takes a description written in a subset
of Occam and generates a high level schematic diagram depicting its
realisation as a VLSI system. This diagram provides the designer with
feedback on the relative placement and interconnection of the operators
used in the source code. It also gives a visual representation of the
parallelism defined in the Occam description. Such diagrams are a
valuable aid in documenting the implementation of a design.
Occam has also been selected as the input to the design system that
COPTS is a feature of. The choice of Occam was made on the assumption
that the most appropriate algorithmic notation for such a design system
will be a suitable high level programming language. This is in contrast
to current automated VLSI design systems, which typically use a hardware
des~ription language for input. These special purpose languages
currently concentrate on handling structural/behavioural information and
have limited ability to express algorithms. Using a language such as
Occam allows a designer to write a behavioural description which can be
compiled and executed as a simulator, or prototype, of the system. The
programmability introduced into the design process enables designers to
concentrate on a design's underlying algorithm. The choice of this
algorithm is the most crucial decision since it determines the
performance and area of the silicon implementation.
The thesis is divided into four sections, each of several chapters.
The first section considers VLSI design complexity, compares the expert
systems and silicon compilation approaches to tackling it, and examines
its parallels with software complexity. The second section reviews the
advantages of using a conventional programming language for VLSI system
descriptions. A number of alternative high level programming languages
are considered for application in VLSI design. The third section defines
the overall ATL system COPTS is envisaged to be part of, and considers
the schematic representation of Occam programs. The final section
presents a summary of the overall project and suggestions for future work
on realising the full ATL system
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