Computerised Effects – 2

Computer-generated effects offer an alternative to practical ones and should be considered when dangerous or messy sequences are called for.

Flames

It is perfectly feasible to create computer-generated flames, but to achieve authenticity demands time and effort. Real flames break up at their edges, softening and hardening and giving off smoke, factors which can cause problems for the computer operator. It is easier to produce practical flames, but faced with the situation of, say, setting fire to the hair of an elderly actress, a post-production method would seem to be the obvious choice.

Texture

Another way in which computer graphics can aid the designer is in its ability to change textures. Libraries of textural effects, available on disks, can be used to change the surface characteristics of any subject being worked on. For example, a map of an arid desert area could appear to be drawn on sand simply by selecting the appropriate software. A room interior could be given alternative wallpaper and fabric designs in the same way, the various patterns and textures being made to wrap themselves around the contours of the furniture and drapes.

Creativity

One of the most important factors of computer-aided design is that it enables designers to experiment. Prototype effects can be displayed on the monitor and changes made before the sequence is finalised. If it were required to show, for instance, a lava flow it would be an easy matter to use a stock shot or some newsreel footage which could be manipulated to perform anywhere within the picture. Perspective could be created by broadening one end and narrowing the other while flames and hot spots could be enhanced by increasing their brilliance or by adding a separate effect. If the lava had to flow around the contours of a grounded spaceship, the effect could be manipulated to flow along a path contained within specified boundaries. The alternative approach, to record the sequence as a miniature, might prove too daunting.

Whatever the choice, it would undoubtedly be simpler to experiment on the computer screen than in the workshop using buckets of simulated lava.

Computerised effects – 2
Faced with the problem of providing a burning wristwatch on a human arm it could be sensible to employ a stored effect programmed to follow the movements of the action. As a technique this can be both expensive and time consuming, but for a short sequence might provide the only practical solution.