Draw polyline with vertex set to surface elevation

[asloat]

I'd like to draw a polyline, likely a 3D one, where each vertex automatically gets its Z value from the surface I am drawing it on.

Maybe there is a better way, so let me explain what I want to do it for.

I need to draw a pipe at an elevation relative tot he surface. So say I want it to be 3' below the surface, I'd draw it at that location using the surface elevations and then offset it down 3 feet to then use as the pipe location for the pipe network command.

[asloat]

Ok I think I figured this out;

Draw polyline, use Edit elevations and use Elevations form surface.

Does anyoen know a command to do this all at once?

[KirkNoonan · Accepted solution]

I would suggest using a feature line. You can tell it to use the surface elevation when you're drawing it and then lower it 3 feet. The good thing about the feature line is that you can create a pipe network from it with the top outside of the pipe being at the same elevation as the feature line. (Create Pipe Network from Object)

[asloat]

That works as well and is a bit cleaner, thank you.

[Jay_B]

One method to eliminate some of the unnecessary vertices's in the Feature Line prior to creating the Pipe Network is by using the Modify Tab>Edit Elevations Panel>Delete Elevation Point. Just slide cursor along Feature Line and the glyph will display at the points.

Modify Tab>Edit Geometry>Weed, can also be used to delete multiple PI's at once.

[annw2]

This is a more complicated question.

I have a flat curvilinear stream with aerial contours.

I have a model based on the contours and two curvy poly lines to represent the stream channel, with a couple hundred curvey feet between contour elevation.

Is there any method that would assign and interprolate the elevations along the polyline (2d) in this case?

I am at home with no access to the help function right now.

[hencoop]

A feature line can contain curves. Make feature lines from them and drape them on your surface. If you need them to be 3-D polys just explode the feature lines. I'm at home and can't check this but I've done this before. I'm not sure if I left out anything.

[Hidden_Brain]

Your question may get better visibility if you start a new thread.

I think you can create feature lines from your channel lines, the start and end elevation of the feature lines will be the two contours. Then insert elevation points on the feature lines by some increment.

If your channel lines has existing vertices, then after creating the feature line, you could set the grade/slope between the start and end point of those feature lines.

[KirkNoonan]

I would convert your polylines to feature lines and use the elevations from surface tool from the feature line tool bar to apply the elevations from your surface to the feature lines.

[annw2]

Thanks Kirk & the Brain.

I was playing around with that this morning once I am back at a CAD station.

The first run was very long runs at 0% slope then short steep drops where the stream channel crosses the contour line.  The stream is a very long curvilinear geometry on a flat flood plain.

I've already done a manual interprolation for my cross sections.

I will play around with this more on the next project.