Copy parallel- I need to keep the elevations of original line.

To "Copy Parallel" a non-planar linestring while maintaining the elevations of the original linestring, try the following:

1. Extrude the linestring vertically using Surface by Extrusion with Keep Original checked. This will create a vertical surface based on the original linestring.
   (I suggest you extrude a generous distance to make step 4 easier.)
2. Use Mesh from Element to convert the extruded surface to a mesh.
3. Use Thicken Mesh to Volume and set the Thickness to the distance you wanted to "Copy Parallel" the original linestring.
4. Use Delete Mesh Facet in Block mode to delete every facet of the mesh volume except the bottom facets.
   (If you followed my suggestion in Step 1 you should be able to select & delete all of those facets in one try.)
5. Using Extract Boundary, set the Extract mode to Boundary Segment and extract the boundary segment that is along the opposite side of the mesh from the original linestring.
   This boundary segment is parallel to the original linestring and is what you want!
6. Delete to mesh as it is no longer needed.

Regards,
Ron

Hi Ron,

An elegant solution without leaving the 3d file  but it  seems like  a lot of effort compared to mlong 2015 suggested export to 2d , then ref back in and drape 2d on 3d surface...I noticed that's what our inroads guys do all the time to set up the control line and chainages ( stationing)

Hi Lorys,

The draping method assumes that there is an appropriate surface upon which to drape. My method doesn’t. 

Ron

Hi Lorys,

The draping method assumes that there is an appropriate surface upon which to drape. My method doesn’t. 

Ron