Interpolate points from existing surface

[marywinkley1386]

I have random points along a water's edge as calc'd at various sections along an alignment. These points coincide with an existing surface. What I'd like to do is to extrapolate/interpolate, from the surface, a 3d polyline that will follow the surface elevations between those points.

Thanks,
Mary

[dgordon]

draw a 2d polyline from point to point and then convert the polyline into a feature line. then sample featureline from existing surface.
then explode it back to a 3d polyline.

Dan

[marywinkley1386]

Thanks for the reply.

The problem is that I need the new pline to follow the downward slope of the surface. It will meander across contour lines to reach the next point. Essentially, I'm trying to follow a flood event line, and all I have is a handful of points with elevations along the sampled sections. If I draw a straight line between points, it tends to cross the river. All of the flood inundation data was created with HEC-RAS, so I was hoping to just use C3D to quickly generate the various flood event lines from these points rather than re-calc.

[bberry]

I might be not understanding. But my immediate first hunch is that you need to create a feature line. Draw a pline that represents this feature that you're trying to super impose onto a surface. Create feature line from object and within that dialog that pops up are options, pick "Assign Elevations" and "From Surface". Just pick the surface and say ok. Explode the feature line and you have a 3d polyline I believe.
Just ignore me if this isn't what you're wanting. 🙂

[Anonymous]

There's an import tool for HEC-RAS export data that will bring in the
river profile data if you can get it from the analysis folks. It comes
in as a profile, which you can then use to drive a corridor or a feature
line and daylight appropriately along the surface from the river CL.

HTH
JW

[marywinkley1386]

Thanks!