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Specialised vs. standardised interfaces


One may consider the use of MIDI and specialised interfaces in music production versus the standardised interface in graphics.

Is electronic music, with its bewildering variety of interfaces from piano keyboards to dials to touch sensors, better provided for than digital graphics? Most electronic instruments allow real-time playing of notes or modification of sounds; nearly all are linked together with the ubiquitous MIDI interface. That is why a “video synthesiser” like the Scanimate might have some advantages over the unified interface of computer workstations.

Dave Sieg explained that a team of graphics users had created a MIDI interface for the Houdini 3D program, where each of the knobs could be turned and affect a different parameter of the image. [1] However, it is evident that computer graphics lags behind music technology in its utilisation of interfaces.

Malcolm McCullough also noted that computer musicians have developed a digital codification of touch in the MIDI standard, which in addition to its basic functions of recording timing and note pitch, allows varying degrees of touch to be encoded. [2] As a user of keyboard synthesisers myself, I know this can also depend on the sensitivity of the instrument itself and the quality of its keys.

However there is little use of touch technology in the sphere of digital art apart from graphics tablets which register levels of touch input from the stylus. As I discovered from my trip to SIGGRAPH in 1999, haptic technology certainly exists, but it is still esoteric and cumbersome, though quite impressive if one allows for its limitations. It does, however, require a significant amount of computing power to calculate all aspects of touch in three dimensions: which partly explains why it is only now beginning to be developed.

The relative advancement touch codification in the field of digital music also says much about the roots of computer graphics in vector graphics and CAD. These areas were based on architectural and technical drawing, where the line is of paramount importance. This in turn gave computer graphics its early distinctive qualities of hard edges and solid, simple areas of colour, which spoke of mathematical perfection but left little room for the fine gradations and indeed imperfections that usually characterise ‘art’.

Because precision was important in the fields where computer graphics was first developed – scientific visualisation, the motor and aerospace industries, etc. – and after this, computer graphics pioneers pursued photographic realism with mathematical models of light and surfaces, the methods of inputting or creating the drawings were left in a basic state. The light-pen, developed for the SAGE system in the 1950s, remained in use as the primary method of interacting directly with a computer display, and was then joined by the mouse in the early 70s. Both are very much two-dimensional devices, made for operating on flat surfaces in ways that simulated pens on drawing boards, which left little room for subtleties such as the force or pressure of the hand when drawing or sketching.

The necessities of performing music forced the designers of the MIDI standard to incorporate it. By contrast, graphics programmers never encountered the need to build touch sensitivity into their systems until quite recently. This was partly to do with complexity and the limited power of graphics computers until quite recent times, but had it been a consideration then a standard of touch sensitivity would have emerged early on. Today’s digitising tablets, by contrast, are bolted on to existing systems and need special support programs rather than being integral parts of any software.

In a related issue, it has also taken a long time for a standard three-dimensional interface equivalent to the mouse to emerge. Much three-dimensional computer imagery is still drawn up in two dimensions with a mouse, and though alternative propositions have appeared, none has yet been incorporated as standard. But then, the computer has yet to escape from its transitional phase and thus is currently a truly three-dimensional engine which is constrained by its two-dimensional heritage, of which the keyboard, windowing operating system and mouse are remnants.

So it seems that although the entire field of computer graphics – and thus much Computer Art – has grown up without the requirement of touch, this will change in the near to mid-future as three dimensional creativity becomes increasingly important. Of the software supporting touch-based devices at the moment, one of the more commercially available packages is Procreate’s Painter. It seeks to mimic natural media, to the extent of replicating not only the effects of oils, watercolours, acrylics, chalks and pencils, but also the materials of canvas, paper and board. In this context, touch sensitivity becomes yet another aspect of “traditional” art to be simulated on the computer rather than included as an integral part of the whole; an expression of complex programming rather than an essential basis of the system.

[1] Correspondence with Dave Sieg – the reference was to the use of MIDI controllers with Houdini 3D graphics software

[2] Ref. to Abstracting Craft