Conceptual Overview
The Information Needed to Create an Instrument
Instrument Visualisations
Access Points
In order for Tao to provide an interface between instruments and devices another key object is needed: the access point. Access points allow forces to be applied to the material and also for the physical attributes of the material to be read off at any point, not just at the discrete set of points where cells exist. This interpolation facility is one of the most important as it overcomes some of the limitations associated with the material being discrete in nature. An example might be trying to simulate a string being stopped to a particular pitch. Without the ability to interpolate the position at which the stop is applied it might not be possible to achieve the desired pitch precisely.
In short, all interactions between Tao's cellular material and the outside world take place via access points. This is probably a good place to introduce the notion of the instrument coordinate system. This coordinate system allows points in the range (0..1, 0..1) to be specified. All instruments, regardless of their shape and size use the same normalised coordinate system as illustrated in figure *. Of course for some instruments such as the circular sheet depicted some points (such as point a) will be invalid. If a script attempts to use such an access point nothing will happen. If the physical attributes are read off the instrument at such a point, they will all return values of zero.
Note also that in the case of the string only the x coordinate needs to be specified.
Conceptual Overview
The Information Needed to Create an Instrument
Instrument Visualisations