3d Polyline along a surface at a specified slope

[NaParks]

I think that a command that would create a 3d polyline along a surface at a specified slope would be useful for creating a diversion ditch or berm.

I do not wish to "drape" a line on a surface, giving the line the slope of the surface under the line.  I want to create a line at a slope going up/down the surface.

There is a similar command in Carlson Civil... http://files.carlsonsw.com/mirror/manuals/Carlson_2013/source/Site_Road_Design/3D_Data/3D_Polyline_b...

Does anyone know of a Civil3D command to accomplish this?

Nick

[Jeff_M]

There is a 3rd party program that does this:

http://dotsoft.com/mwsurfaces.htm look for GradePoly

[TerryDotson]

Many thanks, GradePoly is also available separately for Civil3D 2013 at the Autodesk Exchange Store.

[johnsonbk]

This can be done using corridors and no special outside software.  Create an aligment, use your engineering judgment to create the alignment roughly you think your final swale or ditch would be but offset it to one side.  Create a assembly that daylights to a surface at a 0% slope, you only need one side, create your profile at 1%.  Now create a cooridor on your alignment and profile using the 0% slope assembly.  You should be able to extract the daylight line from the assembly as a 3dpoly.  

Somewhat more involved than a single command but it really isn't as complicated as it sounds.

Cheers

[troma]

Sorry, I disagree.

The resulting daylight line won't have the same slope as the profile used to create it.  It will have the same slope as the profile parallel to the alignment, but it will also slope towards and away from the alignment.  It will therefore be flatter than the profile, since it has more run over the same rise.

[el_nath]

So very much needed! Not just for drainage ditches but for so much more (conceptual rail alignments, roadways, etc.). I'd prefer a featureline, than a 3D polyline, just to be consistent.

CreateFeatureLineAtSlopeOnSurface.