Polyline laying on bathimetry

[enrico_basso9579N]

Hi, I imported a surface from a xyz file that constitutes my bathimetry.

I want to model a pipeline (as a 3d polyline) that lays over the bathimetry.

By drawing the 3dPolyline manually selecting the points they take the z value from the bathimetry but I have two problems to solve:

1. I'd want to divide the 3Dpolyline in evenly spaced segments of a specific length

2. I'd want to extract the xyz coordinates of that specific polyline.

Many thanks for your help.

ps: In first the picture you can see the bathimetry and the polyline. On the right you see the 3d polyline in x-z view and the related bathimetry.

in the following pictures in the property tabs you see that the z changes for the different vertices.

I'm aiming to obtain the same result but for evenly spaced vertices

[will_young]

If you just need the xyz points you can obtain the length of the 3d polyline from its properties, divide this by your spacing length to obtain the number of segments, then use DIVIDE command to generate a point at the required spacings. These points can be converted to COGO points if required or export via DATAEXTRACTION.

Alternatively if you prefer COGO points you can convert the 3d poly to a featureline and use Create Points > Misc > Divide object. 

Just be sure to supress the prompts otherwise it will ask for a description for each point.

[AllenJessup]

You could create an alignment stationed at your specific distance. Then create an Existing Ground Profile. From there you have an option to either set Cogo Points at the stations or use the Divide Alignment command to set the Cogo Points.

Depending on how they were created you may need to specify getting the elevation from the Surface. Then export the points to an ASCII file. CSV or whatever flavor you want.

Another way would be to create a Station report.

[tcorey]

Use Feature Lines instead of 3D polylines. Insert Elevation Point function will let you tell Civil 3D an incremental distance between points along the feature. If you really must end up with a 3d polyline, you can explode the Feature Line later. To get those points to read the elevations from a surface, use the _FeautureElevsFromSurf command.

[Joe-Bouza]

Divide cogo points at your interval and surface will have you the repot you seek.

Why 3D poly? 

[teerawat.pSCHYQ]

hi @enrico_basso9579N , i suggest that you should create alignment from that polyline, and then create profile from your bathymetry surface, then you can design your pipe line, it might be by invert control or center line control, and then you can extract to 3D polyline by each length if you need, this way, you need to create simple corridor and then extract corridor to Feature line, then finally you can have each 3D polylines by specify each length.

[will_young]

Making an alignment is OK if you just need the spacings in 2d, but if you want to measure along the pipeline in 3d this won't take into account the z values. Looking at the elevation values there is a significant elevation difference between vertices.

[teerawat.pSCHYQ]

this is for example if you set invert to be control pipe line at every 30m in 3D slope length, then you can do some thing like this in your profile control like this 

[will_young]

Looks nice. The question asked for xyz points but I agree this would be the best way to present on a drawing.

[teerawat.pSCHYQ]

you can create point on each vertical geometry and can come out xyz point ... that why i suggest to do alignment and profile.  then you can create 

[TodoTerrenoCad]

"Hi enrico_basso. Modeling a pipeline over bathymetry by manually clicking vertices to get the Z-value is incredibly tedious, especially when you need evenly spaced segments for your coordinates extraction.

To solve this exact workflow, I developed a native toolset that automates both steps in seconds:

Step 1: Get evenly spaced segments. > First, just draw your pipeline as a simple flat 2D polyline (or use your existing one). Then, run my custom command TTC_POLY-DENSIFY. It automatically divides and adds vertices along the entire polyline at whatever specific distance you need.

Step 2: Lay it perfectly on the bathymetry.
Next, run TTC_POLY-ON-SURFACE. It instantly drapes that densified polyline onto your bathymetry TIN, elevating all those new, evenly spaced vertices to the exact seabed elevation.

From there, extracting the XYZ coordinates of those vertices using native tools is a breeze.

I packaged these two tools (along with 13 other surveying automation commands—15 tools in total) into the Todo Terreno CAD Suite. It’s available right now on the official Autodesk App Store with a 1-month free trial, so you can test it on your pipeline right away. Hope it helps!"