Yesterday my boss (who still lives and breathes grid paper) came up to me and asked if I could plot a profile from just a single shot of road enterline points that he provided. All he wanted was the centerline plotted. The road was a bit twisty in the plan view.
Making the old new – profile from single points
Knowing how he REALLY wanted me to do this (plotting points stationing and elevations would take an extraordinary amount of time), I thought that Civil 3D should be able to do this no sweat! I told him I’d like to give it go in Civil 3D. His response was “I don’t care, just get it done”.
So, knowing that a profile needs a surface and an alignment, I set to make the alignment. I did the old ‘connect the dots’ and then performed best fit lines and curves to establish a quasi-centerline. I also made a polyline from the point-to point shots with elevation.
Since I had points with elevations, I could create a surface from just those points, right? WRONG! The surface was disjointed and missing places where the surface deviated.
So, I knew that he only was concerned with the centerline and could care less about anything outside of that. But I needed a surface! So, I simply used the good old Feature Line Offset command! Remember that most of these Feature Line commands can also be used with polylines. I offset the centerline 10′ to the right and left – just enough so that I could establish a surface.
I then, created a new surface and brought in all three polylines as breaklines and voila! I had a surface! So creating the profile was a snap. I put a BIG NOTE on ym no-plot layer indicating what I had done and that it should NOT be considered as accurate in any way, shape or form! I do these no-plot notes to inform future designers who might look at my work 20 years in the future and know what my intnentions were. Just another one of my CAD Manager SOP for all drafter/designers.
So, the total time spent on this little project COULD have been hours. In Civil 3D, it took less than a half an hour! AND, I impressed my boss – guess that makes my day complete.
Category: Profiles /