Harrison Eiteljorg, II
The principal aim of CSA Propylaea Project is the creation of a stone-by-stone CAD model of the Propylaea. Work is in progress, and the early results are very exciting. Elsewhere in this issue of the CSA Newsletter, -- "First Fruits of CSA Propylaea Project" -- in fact, are some of the results from the early modeling.
As future work processes were being planned, some subtle changes in aims were made. As a result, the project directors feel it desirable to make explicit the intent to create a dimensionally accurate, fully 3D model that matches the information needs of those working on the building, scholars, and potential future users - without including information considered to be of no value.
A fully surveyed 3D model could be taken to require the independent survey of every point in the model - each corner of each stone. It would be impossible to model stones that have been badly broken and damaged, but, in general, the theoretical aim would be the survey of each point used in the model. In the case of a wall that is flat, a wall lying in a single plane, why would one want, much less need, an independent measurement of the position of each point above or below the surface of the wall? If length and width are properly determined and the orientation of the wall surface properly defined, is that not sufficient? The answer, for the project, is a clear, "Yes." This was not a choice dictated by the difficulty of the survey work but one suggested by the nature of the records already in hand and the needs of potential users. There are sections of walls in the Propylaea for which all blocks can be taken to lie in the plane of the wall. The deviation from that plane might be as much as a few millimeters, not enough to affect any analysis. The position of each stone in such a wall will be specified accurately, and every point in the model will have a full set of coordinates, but points defining blocks in walls that have remained flat will derive one of their coordinates from the plane of the wall rather than an independent measurement.
We realized that this procedure would be used when we began to make plans to survey a flat wall for which the details of each stone had been measured - with the assumption that the stones lay in the plane of the wall. It was obvious to the project directors that the needs of the project were not greater than the needs of those who have been working on the building for so many years - those who were, in fact, well served by the dimensional information already available. While it might have been consistent to insist upon full survey of each corner of each stone, common sense suggests that this is a case where, "A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines." (Ralph Waldo Emerson, Essays: First Series, "Self-Reliance")
-- Harrison Eiteljorg, II
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For other Newsletter articles concerning the Propylaea Project, or the use of electronic media in the humanities, consult the Subject index.
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Table of Contents for the Spring, 2001 issue of the CSA Newsletter (Vol. XIV, no. 1)
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