Construct 3D line

[BenjaminMittler]

Can someone briefly explain to me how construct 3D line works. I just ran the process using a DEM and a stream line to attach elevation data to the vector stream line. How does this tool assign elevation data, at what increments? does it just assign 1 mean value for the entire stream? when i looked in the attribute table of the 3D line i didnt see any elevation information

[BenjaminMittler]

On a further note, i am interested in creating cross section of stream channels using the stream line and the dem i have, are you able to do this in arc hydro?

[BenBurnett]

Did you ever figure this out? I'm having the same problem.

[BenjaminMittler]

I found that for my purpose HEC-GeoRAS was superior in every way. it allows you to draw a polyline shapefile  (accompanied with a stream line) and then simply click on an area and it will display a cross-section profile.