Demonstrations of CAD and the older propylon have shown how important layer naming conventions can be. Good planning adds significantly to the speed of such demonstrations -- and to speed of work generally.
Each layer of a CAD drawing has (in most systems) both a name and a number. One may use either to distinguish groups of layers. For instance, all layers with material of a given date may share a common range of numbers or a common letter in the names. Similarly, layers with hypothetical material may have a common designator.
Computer systems often permit references to labels with "wild card" designations. The "?" can, for example, be used (as in DOS and XENIX) to refer to any single character and the asterisk to any number of unspecified characters. Dealing with numbers is even easier, since the computer can easily select numbers which fall in a specified range. Using well thought-out labels and wild cards effectively permits one to select quickly and easily all the desired layers for display - for instance, all those relating to a given period, whether real or reconstructed, or all the in situ material before a given date. One need only type -- if one has planned properly -- a single group of characters with the proper wild cards to include the desired layers. The more layers used, the more important this becomes, and in complex sites the number of layers can be surprisingly large. (There are 41 layers in the drawing of the older propylon.)
For other Newsletter articles concerning the applications of CAD in archaeology and architectural history or the "CSA CAD Layer Naming Convention," consult the Subject index.
Table of Contents for the May, 1988 issue of the CSA Newsletter (Vol. 1, no. 1)
Table of Contents for all CSA Newsletter issues on the Web
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