Define

Name and define a contour fence.

An exclusion polygon (polyfence) is used as a contour fence during the Generate Contours and Terrace Fixed Slopes functions. Civil Designer allows multiple exclusion polygons to be defined and selected.

The sides of the exclusion polygon consist of DTM lines. No other lines can cross through an exclusion polygon. It would normally represent such items as dams, settling ponds, dunes, etc.

Polyfences differ from Fences in that they fit the shape of the DTM lines that surround the area. You don't click successively to define a polygon as with Fences, but simply once within the area.

To see where existing exclusion polygons are, use the Display command.

Procedure

1. You are prompted to:

PolyFence: Indicate inside desired polygon near a line

2. Click on a position and the polygon formed by the lines surrounding that point are tracked.

Keep the polygon as simple as possible. For complex shapes rather divide the area up into smaller simpler figures by adding additional break lines. Then define multiple smaller polyfences instead of one large one. Then optionally at a later stage after performing the function that excludes the areas, you can remove those fictitious breaklines. This way you minimize the chance of getting unwanted parts of contours that erroneously cross the polyfence.

3. If the polygon was tracked successfully, you should first see the polygon highlighted temporarily in the default pen. If you don't, the polygon area may have been too complex to determine. Simplify it.

4. Secondly, you are prompted to:

5. Type in a new polyfence name.

6. Click OK to continue.

7. The function continues prompting for a position until you press [Esc].