Computer Assisted Traditional Animation – Page 2

        Category: #29 Spring 1992 | Article posted on: December 24, 2010

Edwin Lutz on the subject of animation believability
Taken from Edwin Lutz’s book: Animated Cartoons (published in 1920)

By experience the artist will learn to know where to slight – “slight” isn’t exactly the word, but it will do – the drawing.

With respect to this latter point, suppose there is some arm movement, with the arm swinging as it does in a hurried walk. Hands, it is certain, are difficult details to draw, and if they are carefully rendered in all of the positions it would take a, long time to draw the entire series. But the experienced animator has learned that at times he can, for some of the positions, every other one perhaps, make quickly lined marks indicative of hands. These quickly made Lines, however, must be drawn in a way that will help the action. Exactly how to make them and to what extent to “slight” them is learned only by long experience.

For some quick actions, “inbetween” drawings can be slighted as shown in numbers 2 and 4.

For some quick actions, “inbetween” drawings can be slighted as shown in numbers 2 and 4.
If he moves the arm as if it were a rigid thing, only hinged at the shoulder, the movement would be false and not characteristic of a liking organism. The natural way is an unconstrained, easy bending movement. The animator in his drawings slightly emphasises this manner of moving.

Illustrating a point in animating a moving limb. Above: moving automaton-like with no bending at the joints. Below: moving with various degrees of flexion at the joints.

The graphics were storyboarded, and glazed white clay models of all the characters made. A complex network of black-line polygon co-ordinates were drawn over the entire surface of each model and each co-ordinate fed into the computer’s digital data bank. When complete, the straight lines are electronically rounded to reproduce an accurate copy of the original on the monitor screen. At this stage the figure is animated on-screen in 3D, twisting and turning as the script demands. Colour, texture, lighting effects and camera angles can all be redefined instantly. Once the databases are completed, work can begin in real time.

The soundtrack is read conventionally and plotted. Facial and mouth movements are manipulated by ‘pulling’ the co-ordinates out of true and into the required positions.

The finished result is worthy of their combined efforts and certainly smoother in actions than some stop-motion model films. Its weaknesses are those already mentioned: the timing of movements; lack of motion blur, and the correct apportionment of relative weights. Nevertheless, the exercise is highly creditable and convincing. So much so the French intend to make feature length productions in future. “Starwatcher” will be the first, an eighty-minute dramatisation based on Moliere pictures. Slides taken from initial sequences showed it to be a typical sci-fi concept.

Francois Gamier said they were working on one software program designed to facilitate the articulation of limbs and facial movements based on muscular movement, and another concerning live action converted to graphic movement. He has already participated on a number of films, including Disney’s Tron.

Video System was formed just over three years ago and now employs thirty people. Commercial television work, special effects opticals, and a keen interest in virtual reality and other advanced computer graphics techniques keep the crew gainfully employed.

The Computer Film Company has shown that highly sophisticated systems for the professional already exist. CFC was responsible for the Weetabix television commercial featuring the caricatured images of Jimmy Cagney, Edward C. Robinson and Peter Lorre. It also made all those totally believable milk bottles dance to the tune of the milkman on the Milk Marketing Board commercial.

Mike Bowdry, Chief Executive of CFC told us that Harry works at sixty-two lines whereas CFC operate a high resolution system featuring a large hard disk store with 5000 x 4000 pixel picture quality (compare that to the Apple ‘Quicktime’ image quality 512 x 480 pixels). Their image quality is so good it can be integrated with visuals shot on IMAX. Here is a professional digitising tool permitting the manipulation of fully rendered fully animated images up to cinema standard, not those produced by a computer but pure animation on flat cels, hand painted. Black line-drawings can be coloured electronically but it is more cost effective to colour conventionally, although this cost factor is rapidly changing with present day new methods. A variable colour consistency is no problem. After digitisation, a fixed colour quality is assured. The whole process of transfer takes three seconds per 35mm frame; cels are photographed onto 35mm film, then each frame is digitised, entered on the hard disk, and a back-up made. Mattes are hand drawn for complex scenes involving the interaction of cartoon and live actors either in live action scenes or within a graphic computerised environment.

Colour balance is all-important. During the making of one production a mis¬match occurred when the drawings appeared too garish, too bright and did not gel happily with the subdued shades of the live action. A compromise was reached by toning down all the digitised cel colours and pumping up the digitised live action colours, adjusting the two balances electronically until they achieved an acceptable level.

Matte edges were electronically softened, and shadows of the cartoon characters laid on nearby humans. Electronic blur was introduced to match normal live action blur thus improving believability. This is something computers can do which is denied the film man, who has to make do with dry brush effects.

However, complex electronic rendering work is very time-consuming and is often left to the hardware and software to accomplish during the night hours.

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