Basically, I am asking, how do you offset lines and maintain their elevations? I found another thread regarding a similar topic but it evolved into a VBA and lisp routine discussion.
Not quite sure I follow you here... Maybe you are looking for Grading->Edit Feature Lines->Stepped Offset? This works for Feature Lines, Survey Figures, and 3D-Polylines. Just beware that Autodesk broke it in 2008 SP2, and the offset line loses all elevation points that are not also horizontal PIs.
Unfortunately, you will discover that C3D is not very surveyor-friendly. Autodesk largely has no concept at all of what surveyors do or how they work. Most of their efforts so far have been devoted to the Equipment Database (which is completely useless, since this issue is handled already by the data collectors), and the Survey Database (largely useless, because it doesn't understand GPS, among other issues). They do not understand boundary work at all, or construction calcs, or field data collection, and C3D is woefully inadequate for all of these. They don't even have a good grasp on State Plane vs. Ground coordinates, or US Survey Feet vs. International Feet, both of which are implemented improperly in C3D. They've been getting a lot of feedback on these issues, among others, and we're hoping that the 2009 release will provide some relief, but right now, C3D is pretty limited in its survey support.
That being said, we would not even consider using Land Desktop at this point. C3D is flawed, but still far better than that ancient program. But the only thing that's made C3D usable for us at this point are the routines found in the
SincpacC3D (a free download).
The STAKEFEATURES routine in that set of utilities creates offset points to feature lines. Calc'ing 3' offsets to the TBC around parking lots with that routine is MUCH nicer than it was in Land Desktop. Turn your TBC into a feature line, grade the feature line from the spot elevations in the plans, and then run STAKEFEATURES to calc all stakeout points all at once.