One thing that I like the most on my job (beside helping customers) is that there is almost no day that I come home without feeling energized with something new I learned that day. That also serves as a reminder how much more there is to be learned! In any case, while trying to figure out the best way to help one of our frequent and savvy Civil 3D customer, I came across a workaround that may be helpful for all of us. The issue described to me is that customer created some Feature Lines that crossed other Feature Lines which at the crossing points program created Split (Elevation) Points. At one point those points were very useful in designing process (User trimmed feature lines up to that point so that he can use these split points as starting points when creating new feature lines) but they became a problem when user needed to remove them.
In simple terms, feature line (beside other characteristics) is a polyline that connects points with different elevations. Most often when feature lines cross each other it will be outside of these points with known elevation. As you may remember, Civil 3D is designed to mark all points where crossings occur when none of the crossing feature lines has a true geometry point. Another thing you may recall is these points are marked with white triangles, unlike major geometry points in the feature lines that are colored green. Since these split points cannot be selected or directly edited, the Flatten Elevation command comes as a savior.
There are two ways to visually identify these points in a drawing. One is selecting Feature Line in Elevation Editor and selecting white triangle. Program will display it on the screen as grey triangle at the split elevation point. Another is by using END osnap setting. If trying to draw a line along feature line program may display end snap even though only two grips are highlighted as this image indicates. To confirm this one may use LIST command to list feature line and note 3 points.
So what is that Flatten Elevation savior command suppose to do? This command will specify that the elevations of all selected rows are flattened to either the same elevation as the first row in the selection, or a grade from the start elevation to the end elevation of the selection. Knowing that, at this point we were more interested in removing these points while maintaining grade, we will be using Constant Grade option. So, select feature line with split points identified, right-click and choose Elevation Editor. In the Elevation Editor select last two rows and click on Flatten Elevation dialog to choose Constant grade.
This will remove split point as well as maintain percent grade between points. To confirm the change, invoke LINE command and look for end osnap along the feature line. It should not be there.
Until the next time. Enjoy your day!