Published by Focal Press, 1974, ISBN 0 240 50750 9

This an excellent collection of papers relating to the early years of computer animation put together by John Halas with assistance from Woody Anderson. This introduction gives the Contents of the book, notes about the authors and a Foreword by John Halas.

COMPUTER ANIMATION by

Sherwood E Anderson: Ronald M Baecker: R Barfield: P M Beatts: Nestor Burtnyk: Bruce Cornwell: William D Gattis: Stan Hayward: F R A Hopgood: W H Huggins: Stephen A Kallis, Jr.: Kenneth C Knowlton: Malcolm Le Grice: Paul Nelson: John Oldfield: Tony Pritchett: David Ralphs: M Russoff: Judah L Schwartz: Lillian Schwartz: Myron P Smith: Al Stahl: Edwin F Taylor: F E Taylor: Marcele Wein: Donald D Weiner

Edited by JOHN HALAS

CONTENTS

NOTES ABOUT CONTRIBUTORS

BRUCE CORNWELL
Bruce Cornwell graduated from the University of Wisconsin in Geography. One of his current projects is the use of computer generated film in cartography. In collaboration with his wife, Katharine, he has designed and produced some thirty animated films in mathematics. He was Producer and Consultant to the Calculus Film Project of the Mathematical Association of America and was Research Associate with the computer animation film project of the Polytechnic Institute of Brooklyn, Director of Film Production (Computer Generated Films) for General Computing Corporation, and is on the faculty for Information Processing at the New School, New York.
DR FRANK E TAYLOR and MAURICE RUSSOFF
Dr Frank Taylor is a member of staff of the National Computing Centre, Manchester, England, and has been involved for a considerable time with the problems of computer graphics. He is considered one of the foremost experts in this field in Great Britain.
Maurice Russoff, a mathematician and scientist, formerly with the National Computing Centre, working in the computer animation field. Pole and Polar, made in association with Halas & Batchelor Animation Ltd is described in this chapter.
PAUL M NELSON
Paul Nelson is employed by the Atlas Computer Laboratory at Chilton, Didcot, England, and has been involved in computer graphics and film making for some years. He is also concerned in the development of scientific research on behalf of his organisation, into graphics and film production. Mr Nelson is the Director of the highly successful computer made film, Focus, which was produced entirely at the Atlas Laboratory.
DR KENNETH C KNOWLTON
Dr Knowlton is considered to be one of the original pioneers of computer animation, whose own language BEFLIX, has advanced the technique and range of visual possibilities of the system considerably. He is currently working at the Bell Telephone Laboratories, New Jersey, USA, where, with Dr Edward Zajac, some of the most significant experiments have taken place.
DR JOHN V OLDFIED and ROBERT BARFIED
Dr Oldfield is leader of the Computer-Aided Design Project in the Computer Science Department of Edinburgh University. He has been closely involved in the production of the computer film Calculus in collaboration with Halas & Batchelor Animation Ltd, London using computer display and associated software primarily developed for engineering design.
Mr Barfield is a graduate of the University of Edinburgh. During two summer vacations he was employed in developing computer programs for 2-D and 3-D animated mathematics with the support of Halas & Batchelor Animation Ltd. The Calculus film was produced with the 2-D program.
PATRICK M BEATTS
Patrick Beatts is in the Educational Research Department of the International Business Machine Corporation in San Jose, California USA, where he has acquired his enduring interest in computer animation.
DR RONALD M BAECKER
Ronald Baecker acquired his experience through the Massachusetts Institute of Technology, where he wrote the dissertation Interactive Computer-Mediated Animation for the Department of Electrical Engineering for his degree of Doctor of Philosophy. He is currently with the Division of Computer Research and Technology of the US National Institutes of Health, and will soon become Visiting Assistant Professor of Computer Science at the University of Maryland, USA.
JUDAH L SCHWARTZ and EDWIN F TAYLOR
Judah L Schwartz and Edwin F Taylor are both with the Education Research Centre of the Massachusetts Institute of Technology, USA. Computer films produced at the Centre deal with topics in relativity, quantum physics, chemistry, electrodynamics, and molecular biology.
DR DONALD D WEINER and S E ANDERSON
Donald Weiner and Sherwood E Anderson are with the Department of Electrical Engineering at the Syracuse University, New York, USA. Dr Weiner was the Chairman of the UAIDE Computer Animation Committee in the United States for many years.
ANTHONY PRITCHETT
Tony Pritchett developed his interest in computer animation whilst with London University Computing Services, England. He has previously made some computer generated films of his own, and has been involved with computer made mathematical films for the Open University in Britain through BBC television. He now works full time for the Open University.
STAN HAYWARD
Stan Hayward, film director, scriptwriter and consultant to Halas & Batchelor Animation Ltd received the GEIS award for the imaginative use of the computer in animated film studios. The computerised studio is the basic outline of a project being backed by the NRDC (National Research and Development Council) for application in the animation, film and television industries as a whole.
MYRON P SMITH
Myron Smith is the Production Director of the Computer Image Corporation and deals with the technique of providing direct time communication between the artist/user and the computer, the eventual application of the hybrid (analog-digital) computer systems to the television and film industries, as well as in the area of science and education.
STEPHEN A KALLIS and A L STAHL
Stephen Kallis is a scientific journalist and is involved with the application of the computerised animation stand pioneered by Al Stahl in New York. This may have a significant value to every studio throughout the world.
LILLIAN SCHWARTZ
Lillian Schwartz, artist and filmmaker, has been working with Dr Kenneth C Knowlton, computer-scientist of Bell Laboratories, on experimental films. Her sculpture and graphics are in museum and private collections and have been exhibited internationally. Mrs Schwartz's graphics and films 'aided-by-computer' have been discussed and reproduced in contemporary art, scientific, film and trade journals. Her films made by collaborative effort as well as independently, have been seen at several film festivals.
MALCOLM LE GRICE
Malcolm Le Grice is an independent film maker and Tutor in Film and Visual Communication at St Martin's School of Art and Goldsmiths College London, England. He believes that the future of computer made films will be relevant to the activities of artists who are still using conventional tools.
N BURTNYK and M WEIN
Computer experts and mathematicians working at the National Research Council of Canada in the Data Systems Section. Producers of many computer systems adopted for animation. Made several films with Peter Foldes.
W H HUGGINS
Bell Telephone laboratory scientist co-operating with Dr Kenneth C. Knowlton at the Bell Telephone Laboratory, New Jersey, U.S.A.
F R A HOPGOOD
Leading computer expert in Great Britain working at the Atlas Computer Laboratory, Chilton, Didcot, England. Producer of a number of films for Nuffield Foundation and the Open University.
W D GATTIS
Programmer analyst with the Computer Technology Inc., Arlington, Texas, U.S.A.
D RALPHS
At present 4th year student at Brunel University Uxbridge, England studying definition of multi=colour computer animation.
viii

FOREWORD

It is almost ten years since computer animation was first brought to the attention of the animation industry. Since then the prospect of creating motion with the aid of the computer has excited thousands of artists, film makers, art directors, scientists and students.

As interest in making computer assisted films has grown, the number of film makers attempting to work in this field has multiplied a hundredfold and the facilities for production expanded substantially.

In spite of a firm belief in the future potential of the technique, there is a regrettable lack of knowledge about the various possible approaches and a general misconception of what can and cannot be achieved with the aid of the computer. Because of this the board of directors of the International Animated Film Association decided to initiate this book to assist and acquaint all who are interested in the subject.

Before considering the technical possibilities, there is a fundamental psychological handicap to be dealt with which most individuals have to overcome in the animation industry. It is a fact that the artistically inclined dislike the use of machines; art and design students are usually conditioned during their formative years at the majority of colleges, to an attitude which leaves a sense of distrust towards anything mechanical. Artists and designers must come to terms with the computer as they must with other gadgets operated by electricity, and if they seriously want to utilize the values and facilities, they obviously must learn to use the computer in much the same way as they are using pencils, pens and brushes.

On the other hand, those fortunate ones who know the technique intimately, i.e. computer technicians and programmers, scientists and electronic engineers, may not possess the aesthetic sensibility to function in a field where the end produce emerges in visual form. The ideal situation would obviously be a close co-operation between the two sectors - the technician and the artist. However up to the present such unison has happened only occasionally.

The third solution is a person who can combine both disciplines: but there are unfortunately few of these individuals as yet. Nevertheless, as with most new technological devices, the new generation of film makers and artists are taking to the technique with a natural ease, learning about the necessary computer languages at an early age, so before long the approach will be an integral part of activities in the future. In compiling this book I hope that this group especially will gain substantial benefit from the information which is collated here.

As far as the craft of animation is concerned, unlike many other crafts, this still is heavily dependent on human labour. In view of the great expansion in the use of animation in advertising, in the cinema and on television, in scientific communication, in entertainment and education, mechanisation of the production processes is not only overdue, but is essential to advance the whole industry.

An example of the expansion is the expectation of business from $30,000,000 in 1967 to $100,000,000 by the New York publication 'Top Cell' in animated television serials by the end of 1973. The other areas may expand even more rapidly.

It can be said without doubt that some aspects of computer animation are vital for the animation industry on all levels. During the last fifty years unfortunately, the system of animation has hardly changed. The frame by frame animation of a figure still takes place on paper, traced and painted on to celluloid sheets which are placed over painted backgrounds and photographed frame by frame on to a film negative by the cameraman.

Although the system has created its great masters, in terms of modern technology it is highly outmoded.

The greatest need for mechanisation is in the following fields:

  • in the actual performance of creating frame by frame changes on the film (eventually on tape);
  • in the organization of the film studio ;
  • in the operation of the rostrum camera during conventional photography of backgrounds and celluloids.

Free expression is an essential condition for an animator to work under. This approach is in direct contrast to the mathematical precision of a computer's performance.

In the wider context, however, the animator cannot work in a vacuum. He soon realizes that the production of a film requires the involvement of many other departments and that he also depends on the skills of other people.

The physical labour of hand made animation, even in making a short film of say thirty seconds in length, could take several weeks to carry out.

A feature film containing the production of 250,000 individual drawings would take fifty years of labour if all were to be drawn by one person (this estimate is based on Joy Batchelor's and my film ANIMAL FARM - length 75 minutes).

This assessment of the time element does not include the preparation of the sound track and editing, or the preparation of the script and storyboard, since these functions are not essentially affected by the development of computer animation techniques.

It is not difficult to conclude that it would be of immense advantage to delegate the large amount of labour to a mechanical system, which could be capable of similar performances to the human labour. But here arises a relevant problem however, which must be investigated. No computer technique can adequately replace the skill of the human artist as yet for three reasons:

  1. Its inability to provide the emotional performance of a highly skilled animator in character animation. This refers to the delicate and sensitive expressions of some characters, and their power to generate a mood instantly.
  2. Metamorphosis of shapes. Fast transition from one object to another to create a visual or mental association.
  3. Highly complex textural visual rendering, for example which contain a great variety of light shades.

When computer techniques can catch up with these values is still a matter of guesswork. In the meantime it can already provide a wide range of functions which are borne out by the various contributors' articles.

By 1973 the different computer assisted techniques could provide at least three significant values:

  • creating animated images directly on to cathode ray tubes through digital computers
  • creating animated images through analog computers
  • delegating some of the functions of repetitious work such as cell changes, camera operation, celluloid charting and testing animation (line test) in an animation studio.

All these facilities became so wide ranged that they must even be categorized as a separate technology in their own right.

The success of the first science films on the subject of mathematics and space research by Dr Sinden and Dr Zajac has created some excitement, especially on the level of time-saving in production and favourable economies. Computer made films take far less time to produce and are consequently much lower in cost.

The experiments were described in detail by Dr Zajac in an article which appeared in the 'American Scientist' 10 February 1966, dealing with the abilities of the computer animation system to convert scientifically measureable data into images for visual examination and scientific demonstration. Computer animation was soon utilized in other fields, such as quantum physics, chemistry and medical research.

Subsequent productions which were practically all on scientific subjects, gave a very clear pointer to the technique which can be defined as a communication tool of scientific information. Several hundred films in this form are being made at present by university lecturers and scientists at research institutes, mostly by themselves to illustrate their lectures or to prove a particular point which is best illustrated visually.

For instance, Dr Zajac's film on the motion of a communication satellite could not have been made by orthodox methods. Neither could Dr Baecker's computer film which was devised with a mathematical model of the inner membrane of the ear. The film showed how the membrane behaves under certain conditions. Sound waves entering the ear travel from the base of the membrane to its summit, causing the membrane to vibrate in various ways. The computer film clearly showed the slowed down action, and as there are several thousand vibrations per second, this was the first time anyone was able to study how and what actually happens in response to the spoken word in the inner membrane of the ear.

Another area in which computer animation is useful is in medical research in cancer and heart conditions. The action of the interior of the heart was reconstructed by a research unit in an American university, and through the computer made film both the doctor and the patient could see for the first time in three dimensions, the interior and the exterior characteristic stimulation of the motion of the heart.

Yet another area of activity is in the category of aerodynamics. One of the best known films was made by the engineers at the Boeing Aircraft Company showing how their aircraft would land, before the craft was actually built. They also studied the vibration extremes on the aircraft at the blueprint stage.

The Lawrence Radiation Laboratories in California studied the earth's weather conditions and propagation of shock waves in solid objects through computer animation. The NASA, Langley Research Centre has studied the evolution of disks of stars, and shown the simulation of an isolated disk-like galaxy of between 50 and 200 hundred thousand point stars moving in the plane of a disk. The initial rotation of the stars were computer to show the balance of the gravitational force and for the first time, predicted a pictorial presentation of the phenomenon which would have actually taken a time ratio of two thousand million years. There is little doubt that computer animation is tailor made for science and engineering, and that its application could be justified in scientific research alone. Of course there are the other outlets. These are in the fields of school education, experimental work, advertising, cinema and television films, as well as titling and general test superimpositions to live action films. Future years will witness a great expansion of computer films in these comparatively unexplored fields.

The basic difference between the optical lens performance and recording process of a normal camera which records what it sees, and that of a computer lies in the fact that the latter is in the form of electronic beams which are directed on to the face of a cathode ray tube. The tube is phosphorised so that the image is extremely bright. Nevertheless, the kind of vision produced on the CRT depends on various factors. The resolution on the CRT is one, the choice of method for programming is another, and the link between the photographic camera attached to the CRT is yet another. The receiving capabilities of the present CRT on a normal terminal is 1024 by 1024 resolutions. This means that over a million visual signals can be activated at any section of the viewing screen on the CRT, 1024 horizontally and 1024 vertically. This method provides a very clear picture and a great variety of complex forms. As it is also possible to determine a variety of shading from pale grey to intense brightness, any form could be treated in a tonal concept. The newer CRTs have double the present line facilities, consequently the picture reception will be even finer.

Furthermore, colour filters attached to the camera and the new valves in the computer terminal provide instant colour recording which extends the value of the system. This system can, therefore, provide a very smooth linear picture and movement with total control over time and a variety of possibilities for shading the image where required. The operation is controlled through a number of specially worked out computer languages adapted for film production and which are for the first time described in detail in this book.

Film making with the computer, especially in is pioneering period, is an exacting operation. The pulse rate between the camera attachment and the beam of electrons on the viewing screen of the CRT with the film focused on it must be exactly co-ordinated to avoid the effect of jitter and image spreading. With 35 mm or 16 mm cameras built into the computer as standard equipment and with double perforation register joins, the problem of maintaining synchronism is now being solved ... handling the negative film, as a special technique and knowledge is needed with this unfamiliar and photographically unbalanced material, to avoid it becoming fogged. So is the laboratories' inexperience in handling the negative film. Most of the film unless stated, must be developed for 'high contrast' processing in a bath intended for positive film. Handling techniques with these unfamiliar materials whereby they do not become fogged must be considered as an integral part of computer film production.

Despite the great capabilities of the machine in creating images for animation it is still essential to make a careful storyboard in visual form for the production. Knowing what the computer can handle, one naturally draws and plans the storyboard specifically for it, with the emphasis on the advantages which no other system can offer. Complex moving patterns, movement in perspective and rotation of complex shapes to any degree up to 360 degrees are among these basic visual possibilities - some factors for which one must preplan. Others are the potential for slow motion, for complex forms and for the computer's capacity as a memory store, saving time by being able to recall stored sequences of inserts. Of course, the visual storyboard must be transferred to a machine language which the computer can understand. The function of the languages (and these are numerous) is to transfer the preplanned images direct to the microfilm recorder. Of the three basic systems, two are based on digital computers. These are the Fortran system, which relies on the numerical code, and the Beflix system which is based on a pictorial code and requires much less knowledge of mathematics, and therefore suits the artist better. The third system is based on the analog computer which in fact can provide an instant control of movement, forms and colour. These systems are discussed in detail by some of the leading experts in the pages that follow.

So far, the approach for machine animation is entirely dependent on the availability of computer facilities and few actual film units have their own computer set up to carry out the work. Because of this dependence, film makers had to use the existing facilities and systems available and were obliged to adopt the basic approach of the computer's capability. Most computers depend on some sort of digital system, supported by a high hierarchy of storage mechanism, depending on the sort of route and performance that are intended to provide. So far they have therefore completely depended on the arithmetic and logical operation of the digital computer system, a system which has brought down all complex problems to two basic decisions - 'yes' or 'no' leaving no room for uncertainty.

The basic value of the process demanded a clear understanding of the computer language and the necessity of learning the system, which led to extremely fast answers to the questions posed. As far as economics are concerned, this digital system has not always been the best solution for film production. For this reason the analog system, which provides an additional element of 'maybe' in addition to 'yes' and 'no' can broaden the reference for film work and provide the artist with an essential alternative.

Possibly a combination of both approaches provides the best solution. A computer consisting of such combinations is called a hybrid and has both the strong capability and accuracy of the digital, and the flexibility of the analog systems. The latter can also handle greater visual detail with a direct communication link between the operator/artist and the compositor. Here the artist can have his own drawing transferred and converted on to a special television screen to electrical signals which can be processed by the hybrid computer. By the use of such a television link the artist is able to tell the computer what to animate. The picture which is operated by the artist himself still depends on the resolutions of the CRT display, but it certainly allows him to make changes if necessary from the point of view of pictorial content.

The best known analog system so far is the SCANIMATE developed in Denver, USA.

It is anticipated that while the FORTRAN digital system would be more suitable for research work with linear pictorial content which provides only horizontal and vertical lines and variations of these, like circles and other geometrical forms and the results could be kept on tapes for future reference, the SCANIMATE approach better suits the demands which arise from the day by day servicing of television advertising. The pictorial references are broader and more graphic, and for the time being it is simpler for the artist to operate.

Nevertheless even this system can not provide the pictorial content referred to previously. For such facilities further development, which is inevitable during the next years, must be carried out.

At this stage in the evolution of computer animation, any attempt must be of a pioneering nature. There is no formal tuition available in the subject, and consequently no established tradition. The contributors to this book are without doubt among the world's leading exponents of this new technology. Their background is mainly scientific, although film makers and artists are also represented. From such contrasting viewpoints it is inevitable that the writing should emerge on many different levels. Also, as some experts may be more proficient in verbal expression than others there must be some inconsistency in style and approach is unavoidable. As a rule even brilliant film makers and artists can express themselves best through visual communication.

A further factor is the terminology: as the subject matter is largely concerned with a virgin area of investigation its expressions and conventions are totally new. A glossary of technical terms has therefore been incorporated after the introduction and this should assist those readers who may not easily relate the textual content to the meaning of normal computer terms.

In spite of the limitations of communication in connection with this new technology I am happy to have been able to obtain the co-operation of many of such experts combining the quality of artistry with science.

Possibly the scientists who have the most experience in this field are Dr Kenneth Knowlton and Dr Edward Zajac from the Bell Telephone Laboratories, New Jersey, USA, both pioneers in the development of the digital computer for movie making, and both responsible for evolving a special language (based on FORTRAN) to simplify the process. Dr Zajac's films are specially designed for scientific education, while Dr Knowlton in association with Stephen Vandenbeek, the surrealist artist, has devoted his attention to the textural capabilities of the system, and evolved the language of BEFLIX, which provides for a tapestry type of image of much beauty.

Bruce Cornwell is an artist who also has a considerable range of technical knowledge, and it is to be hoped that readers will benefit from the clear exposition of his work with the digital type of approach.

The newer generation of artists, Ronald Baecker in the USA and Tony Pritchett in Great Britain, both have produced films with the digital system and their experiences, described here, might be of practical value.

The account by Paul Nelson (Great Britain) of his experience in the Atlas Computer Unit at Harwell in association with Bob Hopgood in the production of science films should certainly be useful, especially his methodical explanation of the mechanical plotter and his findings in converting the computer generated images from the cathode ray tube to motion picture negative.

Stan Hayward (Great Britain) has a many-sided talent and experience in conventional studio routines. His work in computerizing an animated film studio, and animation line test, may be ahead of its time, but events will inevitably catch up with his propositions.

Dr John Oldfield and Richard Barfield of the University of Edinburgh, and Dr John Taylor and Maurice Russoff of the National Computer Centre in Manchester, have produced films in association with myself and I am very grateful to them for their detailed description of the technical processes involved in production.

William D. Gattis's Solids Animation Program consists of sub-routine packages, mainly concerned with the following areas:

  1. Supplying motion parameters.
  2. Current applications for the program as it now stands, as well as areas in which the program is suitable for use as an aid to the animator.
  3. Special options - windowing, film 'wipes', vanishing point perspective, hidden line elimination.
  4. Areas of current development with emphasis on the combination of the animation program with a control program for numerically controlled animation stand.

The result of animation program is the provision for figurative animation at high speed. The contribution and research in this particular area is one of the most difficult ones to achieve through computer technology.

Dr Judah Schwartz and Edwin Taylor of the Massachusetts Institute of Technology (USA), although their expositions are very short, do prove the important role of the digital system in scientific research. They show that the specialized small team activities of scientists in universities and research establishments can be communicated with greater clarity and better validity with digital methods than the old fashioned blackboard.

The relationship between fine arts and computers is investigated by Mrs Lillian Schwartz and Malcolm Le Grice (USA and Great Britain respectively). Mrs Schwartz has produced the films Mathoms and Pixillation based on Dr Knowlton's BEFLIX language, to prove that a practising painter of abstract images used to the free brush and canvas relationship, can learn the computer language in a few weeks.

The best known hybrid system so far is the Computer Image Corporation's SCANIMATE. In October 1971 CIC superceded this with another system entitled CAESAR. This dynamic organization hopes to widen their scope even further within 1972/73, and the success and flexibility of their method has already been proved in the production of a great number of television commercials, entertainment and educational animated short films. Myron P. Smith (USA) the Production Director of the Computer Image Corporation describes the system in detail and the background of its formation.

An interesting electronic engraving method based on analog systems results from recent experiments. The electronic controls drive a sensitive stylus over the magnetic coating of the film, and by careful pressure it draws the images on to it. The imprint, when transferred to an optical film, can contain the most delicate and sensitive pictures. This method has been developed by Benzion Landau and Ofer Azrielant.

The future development of computer animation is vital for both the animation and the computer industry. So far however the computer industry has taken little notice of the potential which lies in film production. It is considered as a very small section of computer graphics and the amount of money devoted to it is miniscule compared with other types of research. I am convinced that film production on a broader basis could also be good business for the hardware section of the computer industry, especially if it opens the way to full figure animation in real time performance.

It is estimated that at present only about one tenth of the world's animation output is carried out by computer. This volume consists of approximately 350 science films, 200 television commercials and some twenty experimental abstract films. These figures are really quite significant considering that the technique is still unable to cater for fluid figure animation of the Snow White and Animal Farm form. Within the next ten years the scale might easily tip the other way when perhaps ninety per cent of animated films may be computer aided with the remainder based on conventional methods. Considering the expansion in the use of drawn films, especially for education and instructional purposes, the technique has an inevitable importance in the development of visual communication technology.

With the availability of smaller and cheaper computers and the recently introduced computer time sharing system, it is hoped that many more technicians and artists will have access to them; in the meantime regrettably the price of animation cameras has been rising and so has the cost of production for conventional animation. This is yet another reason for the growth of computer animation. The long, arduous and repetitive production line of animation is no longer acceptable to our way of life. The computer can perform these tasks better and at a very high speed.

In the meantime it is necessary to realize that the development of this new technology is rapidly changing. New systems, new methods are being brought into use constantly and it is very likely that many of the methods described in this book will already be superceded by newer solutions.

Unlike the development of optical film production which took seventy years to evolve to its present stage, this new electronic expansion of cinematography will only take a short period. It is bound to open up new possibilities for the scientist and the artist alike, and establish a bridge between them. I do hope that this book may clarify, illuminate and stimulate the process.

John Halas London 1974

ACKNOWLEDGEMENTS

To the authors and their respective organisations, including the Society of Motion Picture and Television Engineers {USA), for contributing the wide variety of material contained in this book.

To Robin Fairfield for contributing a glossary and checking proofs, and to Robert Leach for compiling the index.

INTRODUCTION

As the computer is capable of transferring at a high speed, impulses which can be easily made visible on a cathode ray tube in the form of moving images, there is no reason why such such an advantage should not be used by film makers, educationalists and scientists.

During the last ten years the production of computer made films has spread quickly, not unlike the rapid expansion of cinematography during the period of 1920-1940, and today several hundred scientific establishments and film studios are involved throughout the world.

In this book experts in the technique and in the art of computer generated films, reveal the latest methods and systems which are being used. It is clear that animation will never be the same again! There is no turning back.

Computer made films have already proved they have great practical application as well as exciting artistic potential. For the moment the process of computerized animation can only be carried out in the form of moving images. Live action cannot yet be considered on its own - only in combination with graphic animation. Consequently the technique needs the participation of animators, designers and layout artists.

The process however, demands a substantial departure from accepted methods and requires new tools. The graphite pencil becomes electronic, the storyboard turns into a sensitive cathode ray tube capable of generating thousands of electronic signals per second. The new language must be learned just like the skill of flying or driving a combustion engine or tapping the keys of a typewriter.

The reward is a widening of vocabulary in visual language and experience. The keyboard is already in existence and universally approved, both by the artist and the scientist. Nothing as important has happened in animation for a very long time.

GLOSSARY

ACCESS
To ACCESS data is the process of locating and retrieving information which has been previously filed in the computer store.
ACCUMULATORS
Store location for arithmetic results.
ADDRESSES
Location in the computer containing an instruction, or item of information.
ADDRESSABILITY
The way in which an item of information is transferred to and from its address.
ALPHANUMERIC IMAGES
Display of both letters and numbers. Could also include special characters.
ANALOGUE COMPUTER (ANALOG)
Where the result is shown by analogy. e.g. increasing stress may be shown by increasing voltage. As against a Digital computer which shows the results as numbers.
ANALOG DEVICES
Special purpose devices that count or compare by comparison (usually by voltages).
ARRAY
An arrangement of data items identified by key or subscript. e.g. the days of the year could be named 1-365 (1 dimension array) or they could be named as part of the month 12.6.71 (2 dimension array).
ASSEMBLY
A symbolic language used for ease of writing, but must be converted to machine code (in the assembly) before it can be used.
ASSOCIATORS
Memory stores whose locations are determined by content rather than address.
BATCH-MODE
implies the kind of operation of a large computer where the user cannot directly communicate with the computer via a terminal, but submits his job as a deck of cards, or a paper tape, to an operator who runs his job for him, together with others, in a batch. He must return later to collect his output.
BATCH MODE PROGRAM
A program for handling a 'batch' of information (stack of punched cards etc. Not a real time operation).
BITS
Binary digits.
BIT PATTERN
A sequence of Bits.
BINARY INSTRUCTIONS
computer instructions use binary arithmetic in place of our more customary decimals. This means that the only digits used are 1 and 0.
BYTES
A set of Binary Digits (Bits) usually a subdivision of a 'word' (a basic unit of data in a computer memory.
CAL COMP LINE
On-line to a Cal-Comp plotter.
CALLS
A branch to a closed sub-routine.
COMPILER
A complex program which converts computer instructions written in a source language into machine code.
COMPUTER FACILITY
The characteristic ability of a computer.
COMPUTER LANGUAGE
in order to communicate with a computer it is necessary to know a specific vocabulary and the way of using it. This would generally take the form of written instructions, which can then be interpreted and obeyed by the machine.
CONTINUOUS ANIMATION
Interactive system of animation as against pre-programmed graphics
CORE STORE
Computer memory composed of magnetic cores.
DEBUGGING (program)
Checking why the program will not work.
DEBUGGING (runs)
Using a standard test to see if the program works.
DESIGNER
One who conceives the original idea and evolves the basic artistic groundwork.
DIALECT
A variation of a standard programming language.
DIGITAL COMPUTERS
One that performs on data presented in a digital form (numbers).
DISK
A computer storage device in which data are recorded on a number of concentric circular tracks on the surface of magnetic disks. Information can then be selected and read at extremely high speeds by the computer, as required by the animator.
DUMPING
Method of running a program so that in the event of stoppage, the program will continue from where it stopped, and not start again from the start.
ENCODER
A device which reads out the angular position of a shaft in a digital form. The encoders can be used to control the position of a picture element on the CRT screen, including its rotation about any desired axis.
FLYING SPOT SCANNER
Device in cathode ray tube which emits electrons onto the screen
FORMS CAPABILITY
Method of mechanically moving the forms (stationery) in a graph plotter.
FORTRAN
An acronym for FORmula TRANslation. It is a problem oriented high level programming language.
GAUSSIAN CURVE
A statistical distribution curve - eg it plots the frequency of an event.
GOTO (GO TO)
A computer program instruction which causes control to be passed unconditionally to another part of the program.
GRAPHICS
Output in graphical form on the cathode ray tube or graph plotter.
HARD COPY OUTPUT (Camera etc.)
A document in a form suitable for human beings to read produced at the same time as information is produced in a language suitable for a machine.
HARDWARE
The physical units making up the computer system.
HIDDEN LINE PROBLEM
In graphics, the problem of making a moving line disappear when it seems to be passing behind another line that represents a solid.
HIGH LEVEL LANGUAGE
Written instructions are fed into a computer and each command is translated by the machine into one or more basic functions which the computer can then obey. The greater the number of basic steps and calculations produced from each written instruction the higher the level of the language.
HYBRID COMPUTER
A combination of two distinctly different types of computer, which takes advantage of the most useful and applicable features of each. A DIGITAL computer operates using numbers (ie it counts and tabulates) and has a large information storage capacity, whereas the ANALOGUE computer uses the relationships between electrical voltages to formulate results, and also has a much greater flexibility in reacting to constantly changing situations.
IF
Pass control to one of several named locations, the actual one conditional on values of specified parameters.
INCREMENTATION (system of)
A system for processing changes in variables which may be shown on an incremental display (ie visual display unit).
INSTANCE
Occurrence
INTERFACE (between modules)
This term is used to refer to the channels and associated control circuitry that provides the connexion between a central processor and its peripheral units. Also used more generally to refer to the connexion between any two units.
INTERRUPTS (generated with a light pen and keyboard)
A break. in a program or routine caused by an external source, which requires that control should pass temporarily to another routine; eg to monitor an event which may be proceeding in parallel to take action as a direct of an event which has taken place. The interrupt is made so that the original routine can be resumed from the point at which the break occurred.
INITIALISATION
A process performed at the beginning of a program or subroutine to ensure all indicators and constants are set to preconditions and values before the routine is obeyed.
INTERACTION (of graphics)
- INTERACTION (pictorial etc.) Human intervention in a program, achieved either by a keyboard (graphics) or by a pen on a visual display unit (pictorial).
INTERACTIVE GRAPHICS TERMINAL
A unit whereby graphical information may be passed from computer to human being and back again.
INTERACTIVE
describes the kind of computer where a user can communicate directly with a computer through a terminal, and can interact directly with his program, while it is running. Most terminals consist simply of an electric typerwiter, which can only handle data in written or alphanumeric form. Interactive animation requires a much more sophisticated graphic terminal with a video display unit and a light pen (or some other form of graphic input).
KEY FRAME ANIMATION
the animator 'draws' directly onto the CRT display and produces a basic picture or cel. A number of these drawings can then be superimposed on one another to form a composite cel or Key Frame. Many of these key frames can be made up and stored away in the computer to be called and used as required. The action of the film can be created by stringing together the series of key frames, and introducing the desired movements 'in-between' one and the next. Each key frame can be used over and over again by simply calling it repeatedly from the computer store.
LANGUAGE
A set of representations, conventions and rules used to convey information.
LANGUAGE (low level)
A language in which each instruction has a single corresponding machine-code equivalent.
LIGHT PEN
A highly sensitive photo-electric device used with a visual display unit. The operator can pass the pen over the surface of the screen to detect images displayed on the screen, or to change or modify images which have been displayed.
MACRO
a collection of separate functions or objects grouped together under one identity. Hence reference to the one name would automatically bring into operation all the individual functions without the need to mention them singly.
MACRO LANGUAGE
A computer language based on a low level language but enabling single terms of the macro language to activate a complex series of operations.
MENU
a list of the different picture control functions available to the animator in the computer program. He can select a function or mode of operation in whatever sequence he chooses to produce the desired effect.
MICROFILM
miniature reel of film capable of recording many hundreds of individual frames. These can be viewed using a magnifying process.
MICROFILM RECORDER POST PROCESSOR
Output module which produces information on microfilm rather than punched cards, paper tape etc.
MICROFILM PLOTTER
A device which automatically draws graphs or other pictoral data onto microfilm.
MODE
A particular method of operation for a hardware or software device. For example, a particular unit might be capable of operating in, say, binary mode or character mode.
MOUSE
a small hand-held object which can be moved freely over a horizontal surface in any direction. The direction of movement is directly reproduced on the CRT screen as line of light, and thus the mouse can be used as a pencil by the animator.
MULTI-PROGRAM
implies that there can be several programs in the computer at the same time, all at various stages of execution, and time-sharing the computer's central processor.
OFF-LINE
referring to the operation of any device which does not involve the use of the computer's central processing unit.
ON-LINE
Referring to the operation of any device which is under the direct control of the computer's central processing unit.
OP CODE
the element of a computer instruction which acts as a key word, and specifies and defines the precise action to be taken by the machine.
ONLINE SYSTEM
(re typewriter terminals) A part of a computer is on-line if it is directly under the control of the central processor, which directly supplies the output.
P-CURVES
a probability curve is the outcome of plotting on a graph the distribution of results when only two choices are possible. For example - when tossing a coin it can be statistically shown that there will, on average, be as many heads as tails. The possible tendency towards more heads or more tails is far less likely, and this can be shown in the form of a graph.
PIN REGISTRATION
The manner in which drawings in a sequential order are kept in alignment with each other.
PRINT-OUT
A general term for the output from a printer, printed pages produced by a printer.
PHOSPHOR DECAY
The screen of a visual display unit is composed of phosphors which fluoresce when an electron strikes them. The phosphor ceases to fluoresce a few milli-seconds after contact, and this is phosphor decay.
PROBABILITY
The likelihood of happening.
RASTER
A measurement of the number of horizontal or vertical points on a CRT screen. Hence the distance between any two vertical or horizontal points is known as a raster unit.
RESOLUTION
Literally the point on the CRT screen onto which the electronic beam is focussed. Thus the greater the density of signals per unit area, the clearer the image produced.
RINGSTART
The first member of a link to the computer. It is distinguishable from the remaining members and points to the first useful member, if the link is non-empty; otherwise it would point to itself.
RING
A computer held list of items having some common property, e.g. the values of the three angles of a triangle. Each member of a ring points to the next, with the last one pointing back to the first which is known as the ringstart.
'SAVE' CALL OR SEQUENCE
An instruction or series of instructions within a program which tells the core store to preserve some items of the program in machine code for re-use in another program.
SUBPROGRAM
When several programs are being run through a computer at the same time (multiprogramming), it is possible to designate segments of a program or subsidiary programs as subprograms.
SUBROUTINE
A part of a program which performs a logical section of the overall function of the program. Subroutines may be written for a specific program or they may be written in a general form to perform operations common to several programs.
16MM FILM SHUTTLE
The mechanism in a 16mm film camera which propels the film through the gate and onto the take-up spool.
STACK
a distinct section of the storage area capable of storing one array.
SCOPE
the CRT visual display screen.
SYSTEMS ANALYST
A person who analyses methods of doing things and designs and implements new and better methods. He determines how best to use a computer in each new context.
SOFTWARE PACKAGE
A collection of programs and routines which performs input and output operations, or any generalised program written for a major application in such a way that a user's particular problems of data or organisation will not make the package any less useful.
TORUS
a semi-circular projecting moulding, especially in the base of a column.
VECTORS
connecting lines between points which can be defined and identified on the CRT screen.
VECTOR PLOTTING VECTOR MODE DISPLAY
is a method for presenting data on a visual display unit in which vectors are displayed as straight lines between points on the screen.
VECTOR END-POINT ADDRESS
The location in the core store of the character which denotes the end of a vector.
X-Y PLOTTER
Also known as a data plotter. A device designed to give a visual display, usually in the form of a graph on paper, by plotting the course of co-ordinates.
X-Y DIGITIZER
A device which can convert a physical quantity (ie an analog measurement) into coded character form for visual display.