Civil Geometry Trim Extend

Many of the Civil Geometry commands provide a trim extend option as part of the promp sequence.  For example, in the beginning of the video below you see the Arc Between Elements command creating curb returns for the intersection.  In addition, the Geometry commands are fully integrated with the Microstation Modify commands.

So, whether with the Geometry commands or with the Microstation commands the functions such as trim, extend, partial delete and etc are possible.

But consider the intersection in the video below.  If we allowed the partial delete or trim function to proceed purely in a graphical sense then the intelligence on the geometry would be lost.  So we have provided a mechanism to preserve the original element which contains the rule.  So before we look at the video, let's consider the following concepts that control how things work:

  • The original rule is always maintained unless you (the user) explicitly discard it by drop the element or right click > remove rule.
  • Portions of the element which get trimmed are gaps.
  • Portions which remain visible are called intervals.
  • The locations of gaps and intervals are maintained by rule and thus update based on changes.

So in the video you will see:

  1. We start with an very simple intersection: two alignments and 4 edges of pavements
  2. Then I inserted the curb returns on every quadrant.  The edges of pavement will seem to disappear.  But remember from above.  We always preserve the original rule.
  3. As the curb returns are added then the apparent loss of data on the edges of pavement are resolved.
  4. Then I perform a series of edits to the alignments.  Note that because the gaps and intervals are stored by rule then the curb returns are always updated.


Click here to play this video