Engineering conceptual design can be regarded as that phase of the engineering de-sign process during which the designer takes a specification for a product to be de-signed and generates many broad solutions for it. Each of these broad solutions is generally referred to as a scheme [7]; however, in this paper we will interchangeably use the terms scheme, design and concept. It is generally accepted that conceptual design is one of the most critical phases of the product development process. It has been reported that more than 75% of a product’s total cost is dictated by decisions made during the conceptual phase of design and that poor conceptual design can never be compensated for at the detailed design stage [10].

The technology presented here has many features that are crucial for supporting designers during the conceptual phase of design. For example, designers can specify an initial statement describing the desired properties of the required artifact. The designer is free to modify this at any time by adding/removing constraints. Further-more, the designer has the freedom to approach the design process in any way he wishes.

The hardware technology that underlies computer systems has improved so rapidly and continuously for more than four decades that the ground rules for system design are constantly subject to change. It takes many years for knowledge and experience to be compiled, digested, and presented in the form of a book, so books about computer systems often seem dated or obsolete by the time they appear in print.

Even though some underlying principles are unchanging, the rapid obsolescence of details acts to discourage prospective book authors, and as a result some important ideas are never documented in books. For this reason, an essential part of the study of computer systems is found in current and, frequently, older technical papers, professional journal articles, research reports, and occasional, unpublished memoranda that circulate among active workers in the field.

Version 11 of the Unicon language includes 3D graphics facilities. This document describes the design of the Unicon 3D graphics facilities, and provides several examples detailing their use. Most application programming interfaces for writing 3D computer graphics applications are complicated and difficult to master. Toolkits such as OpenGL [OpenGL00] and Open Inventor are powerful, but several weeks or even months are needed to gain proficiency. Even after gaining proficiency, many lines of code are required to implement most features. There is much that can be simplified.

Unicon [Jeffery03] is a superset of the Icon programming language [Griswold96] that offers many features that minimize the time and effort spent programming. Programs written in Unicon require from two to ten times fewer lines of code than programs written in languages such as C, C++, or Java. This report describes a set of simple, easy to use 3D graphics facilities for Unicon.

Computational geometry is the branch of computer science concerned with the design and analysis of algorithms for geometric problems. Among the tools of computational geometry there seems to be a small set of techniques and structures that have such a wide range of applications that they deserve to be called fundamental, in the same sense that balanced binary trees and sorting are fundamental for combinatorial algorithms in general. In this paper we will discuss and illustrate a number of these fundamental techniques of computational geometry. In most instances we give a worked out example of a problem solved by each of the techniques we discuss.

Historical note. The term "computational geometry" was originally coined by Robin Forrest [23] to denote the study of computational techniques in the realm of computer-aided geometric design. More recently, this term has been used to name a somewhat different field, in a way broader and in a way narrower than Forrest's conception, a field which is now considered part of theoretical computer science. This new use of the name "computational geometry," whose origin can be traced to Shamos [65], refers to the design and analysis of algorithms for all kinds of geometric problems, not necessarily in computer aided design. This is the sense in which the term will be used in this paper.