Using islands and island detection
Islands are closed loops that reside inside other closed loops. progeCAD provides island-detection options so that you can specify which islands, if any, should be considered in the area selection for a boundary.
The following figure shows a rectangular polyline with two islands. The circle is referred to as the outer island, and the octagon is referred to as a nested island.
Rectangular polyline (A) with outer island (B), with point (C) specifying the area selection, and nested island (D).
You can choose from three island-detection methods.
- Nested Islands The outer entity and all its islands are considered for the polyline.
- Outer Only Only the outer entity and its outer island are considered for the polyline.
- Ignore Islands Only the outer entity is considered for the polyline.
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Selecting an area for hatching
Specifying a hatch pattern