Create stream from polyline


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Is there a way to convert a polyline to a stream feature ?  My property has an irregular width creek running through it and I have created the polyline with the help of the surveyors drawing but cannot for the life of me figure out the conversion process, if possible.

 

I have tried just following the path with the Chief stream tool, but that just creates a constant width throughout.

 

I also tried using the stream tool and then converting to polyline so I could edit but that turned out to end up with the same situation, getting it back to being a stream.

 

Any suggestions greatly appreciated.  Plan attached.  Creek polyline is on layer names CREEK.

 

terrain with creek.plan

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A quick way to do this is to make a stream in plan, which as you point out is a constant width, then draw an adjacent slab or polyline solid and use the "Union" tool to combine them so that you will get a merged object that still has the "hole" in the terrain effect of the stream, but you will then get all the adjustable handles so you can adjust the shape as you need.  You can make a really small slab next to it and adjust it away later, but that will get it to show all the adjustments while still retaining the stream terrain features.

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You're overthinking it...

Click on the polyline, use the convert tool and make it a TERRAIN FEATURE (that's what it is), assign the water material, done. 

 

30 seconds.

image.thumb.png.5c8dcefde47ae625254739a7ea377c62.png

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Joey,

Although it looks correct in a zoomed out view, a Terrain Feature is not accurate as it will only sit on the terrain.

Have a look at it using a TF in a cross section and you will see that the top surface of the water is not level, it goes up and down, following the terrain.

What is needed is an object who's top surface is horizontal in cross section, yet follows the general slope of the creek as it falls down the terrain.

The hard way would be to shape the creek using Elevation Lines running across the creek and then use a TF for the water.

Or...a 3D Molding Polyline (with say..a rectangular molding) following the slope of the creek and just let the molding cut into the terrain.

 

Here is a really quick down and dirty one using a 3D Molding Polyline - not really great:

 

Screen Shot 2021-04-12 at 12.15.02 pm.jpg

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I agree with Glenn’s general assessment.  It’s only going to be an extremely rough approximation though because water needs to be contained by the creek bed/river bank and as such: the terrain itself needs to be more accurately defined first.  The terrain in the attached example will result in a creek notably different than the one drawn in with CAD.  First fix (or at least refine) the terrain definition and then the creek will be much easier.

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Another way might be to create a terrain for just the creek.

Save it as a symbol and place it on the main terrain.

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OK, that's the way to go.

Copy and paste/hold position the creek polyline and the terrain elevation data into a new plan.

Convert the creek outline to a terrain.

The copied terrain elevation data, along with some terrain data editing to give a level top in cross section, will shape the creek. 

Save it as a symbol.

Insert into original plan.

Once again, not perfect, but does the job.

The creek level and shape is going to change anyway with more or less rain!!!

Took about 15 minutes.

Screen Shot 2021-04-12 at 3.20.38 pm.jpg

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I'll stick to my original assessment, overthinking. If this creek doesn't have to do with the construction or design of the structure, then we have all wasted too much time on it.

 

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7 hours ago, joey_martin said:

I'll stick to my original assessment, overthinking. If this creek doesn't have to do with the construction or design of the structure, then we have all wasted too much time on it.

 

 

If we're talking about simple construction documents then I'd tend to agree.  If it's for more accurate 3D renderings or more detailed site analysis then that's a whole different ballgame and I'd say every example solution given so far misses the mark.  For an accurate stream with anything but a perfectly consistent width, the terrain needs to be drawn to suit.  There's no "quick" method until that happens.

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Thanks all.  Converting the polyline to a terrain feature worked well enough for me to satisfy the geotechnical engineer for proof on concept on what we were trying to accomplish.  Note to self: when creating a new layer for the polyline make sure to turn that layer on in 3d view, oops.

 

This community is so awesome :)

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