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Modelling a river channel


Matt D

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I want to model a river channel. I've tried using the Roadway tool, but this only gives me parallel sides in plan view which is obviously not suitable for an organic forms. Does anyone know of a way of modelling a river channel and placing it on the DTM?

Many thanks

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  • Vectorworks, Inc Employee

One method I did for a presentation, was to create the Site Model from tracing contours (did not have the contour files to utilize) made them 3D polys, then selected them to make the site model. The contours were from both sides of the river that bordered my project. I chose to retain the lines in the source data for the Site Model, and right clicked on the site model and chose to edit the source data, then selected just the polylines on each side of the river..copied and then exited the edit mode, then pasted in place the two 3D polylines. With 3D poly tool, connected the two end points on the top and those on the bottom and then composed to make a 3D polygon. This polygon can now be textured for 3D, which you can apply a water texture, and there is a new one in 2009 that resembles a water surface that shows the shine from the sun. Now, because we have a tool, such as the landscape area, you can use this one object as a 2D representation with color/gradient, and then use the texture on it to mimic the water surface for 3D. The landscape area texture will act as a texture bed on the site model. So the difference is to take the lines composed to make the 3D polygon and make it a landscape area, instead.

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A channel of water in a river bed has some tilt to it. Many rivers are sort of podium/fall, podium/fall. A closed poly with proper tilt and z value can represent the surface (or a group of polys can represent the various podia). These polys need only be wider than the channel at water level. You can cut them at the water edge, but then they are difficult to identify. When rendered, the parts beyond the water edge will be embedded in the channel sides revealing only the water surface. Worked for me, anyway.

The falls are difficult, esp if there are a bunch of bolders. Perhaps an image prop with falls photo texture could pass through the bolders of the fall.

-B

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Download HighRoad from

http://www.createng.com.au/evaluate.php

And import your surveys data (XYZ text file from data collector or total station or GPS), generate the DTM to you liking including adding breaklines at the bottom of the river and both river banks and export as DXF to VW09...

If you want to add any works or design to the natural river course, then add a NEW CONTROL LINE, PROFILE and TYPICAL CROSS SECTION in HR and voila!

Dont need to reinvent the wheel!

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Miguel

Is it possible to provide a sample Vw file to show how the channel was designed within Vw (source survey data, profile, x-section, etc?

I received this message from you in January - "In order to help you out in your workflow, I need more information on how do you use the polylines." I sent a private message with a Vw file attached showing my use of polylines, did you receive it?

Any assistance would be greatly appreciated as this is a difficult time as I am undergoing radiation treatment for neck cancer.

Thanks

Bruce

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Bruce,

I am sorry that you are undergoing radiation treatment and I hope everything turns out for the better.

The channel design file was done in VW9 and it is about 46MB so I do not know if it will be of any use to you and if I can even uploaded it. The project was to widen 8,200 ft of an existing channel which accounts for the large file size.

As you very well know, any kind of civil engineering design is not possible with the tools provided in Landmark. Most of the design I do is accomplished with custom plugins and menu commands that I have developed over the past 8 years. Programming these tools is simply the automation of the steps needed to do a task manually. First, I draw a custom centerline that holds the stationing and serves as the reference point for sections and profiles. Sections are drawn from the data contained in the DTM at the station desired. After one enters the station, the section plugin finds the point on the centerline, draws an imaginary perpendicular line, and calculates the elevation for each intersecting point of the perpendicular line with the 3D poly in the DTM. I would estimate that if I had to do this process manually, it would take me about an hour to draw each section and a total of 82 hours for all the sections in this project. With the custom plugin, it only took seconds to draw each section and about 2 hours to compose all sections.

But the question at hand was how to model the river/channel on VW and to do this, you only need to generate a DTM. If this is an existing channel, you just need to add 3D polys to the DTM that define the top bank and toe of the channel. If it is a new channel, copy all the stake objects or 3D points to a new layer; draw polygons to define the top of each channel side; then, remove all the stake objects or 3D points within the left and right boundary polys; add stake objects or 3D points on each vertex of the polys that define the top and toe of the channel; send the stake objects or 3D points on the top bank to the existing DTM surface; calculate the elevation of the toe stake objects or 3D points; convert the 2D polys to 3D polys; snap each 3D vertex of the polys to the corresponding stake object or 3D point; and finally, generate another DTM with the new channel geometry.

If I remember well, I could not open the file that you sent me because it did not include the extension needed in windows. Nevertheless, I tried to open it with VW 2008 (*.vwx extension) but it failed and I assumed that it was created with VW 2009.

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