The default method is quick contours - in this
method Civil Designer dynamically calculates the
contours. This means that as you modify the breaklines
or move points, the contours will update
automatically. The second method is generated
contours - in this method the contours are stored
in a contour file, and therefore the contours are not
updated dynamically.
The beauty of the generated contours is that it
dramatically improves the re-draw speed of large
projects because instead of recalculating the contours
during the re-draw the program reads the contour file.
Generated contours can also be labeled.
Due to the different way the 2 methods calculate the
contours, on certain projects, the generated contours
might look a little strange. A common problem for
generated contours is a strip survey, with a large
open area in between (contours will cross over the
open space).
Below is a figure of a typical site with quick
contours. Note how the contours are only drawn where
there is data.
The following figure shows the same site, now using
generated contours. Note the open area where the
generated contours cross the open space.
To overcome this problem, exclusion polygons need to be used.
Select the Terrain Mode and the Model › Define
Polyfence option.
Click within the area that needs to be excluded, Civil
Designer will shade the selected area and allow you to
name the polyfence. Multiple polyfences can be
defined.
If the polyfence needs to be deleted use the Model › Remove
Polyfence function.
Once the polyfences have been defined generate the
contours again with the Terrain › Contours from
lines option.
Make sure that the Use exclusion polygons option is selected and
click OK to continue.
A dialog will appear listing the polyfences in the
project, the user can select which polyfences to use
(multiple selections are made by holding down the
shift key and left clicking with the mouse)
Click OK to continue.
The generated contours are now re-calculated using the
exclusion polyfences.
Note that the open area no longer has contours crossing over. |
