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Polygonal Reconciliation


Polygonal definitions in 3D space (Three Dimensional Visualization) are effective methods of selection, but they require an additional constraint. SADA deals with the third dimension (depth) by layer. Therefore, polygons are drawn by layer in 3D applications, and the Space Definition Manager (SDM) records these multi-layer polygons along with the correct depth. If the layering scheme changes, then it becomes unclear how the polygons should be assigned when they are recalled through the SDM.


For example, suppose that a space definition named “Area of Concern” was drawn with multi-layer polygons. The number of layers was 5 and each layer was exactly 3 feet in breadth. Since that definition was created, the layering scheme has changed to 4 layers with the first two having breadth of 2 feet and the last two having breadth of 5 feet. When there is an incompatibility with the defined space layers and the current layering scheme, SADA prompts the user with a new window that contains all the polygons in the polygonal definition (e.g. Area of Concern).







The user may draw and edit polygons in the Graphics window (left) or can drag and drop polygons from the Collection window (right) onto the Graphics window.


Note: polygons retain exact vertex coordinates. Therefore, when a polygon is “dropped” in the Graphics window, it will adjust its size and move its position so that the vertex coordinates coincide exactly with the current coordinate system.