Best way to Convert LDD to Civil 3d?

[Anonymous]

Everyone knows there's a million ways to get from Point A to Z in Autocad, however, I"m looking for a sure fire and most effective way to take LDD surfaces and convert them or paste them into Civil 3d. The way I currently do it is by Exporting the LandXml from LDD and then inputting into Civil 3d. However, I'm finding that it doesn't always give the best results. Also, I would love to be able to copy over the breaklines, if possible at the same time.

What have you guys done that works, and what process should I stay away from?

I'm good in Autocad and know my way around but I would love to hear from some of you that might have more experience. Thanks! 🙂 

[Neilw_05]

I've never had a problem using the Import Land Desktop tool.

[Anonymous]

I tried using that function and I couldn't select my DTM information (i.e. My existing ground surface). So that's why I used the other method. Any ideas why I couldn't use the dtm information?

[tcorey]

As long as you're willing to keep the .tin file around, use CreateSurfaceFromTIN command. This eliminates the need to export to LandXML and just reads your LDD surface directly.

If you don't want to hold onto the .tin file, you can Import 3D Lines in LDD and then save the drawing. Open that drawing with Civil 3D and make a surface from those 3D Lines as breaklines.

[Anonymous]

When i do the "createsurfacefromtin" command it gives exact same as landxml.. Will LDD & Civil 3d surfaces never line up perfectly (contours)?

[tcorey]

If there is a small shift, possibly one dataset is in International Feet and another is in US Survey Feet.

[Neilw_05]

The Import From Land Desktop tool reads the Land Desktop surfaces in the Land Desktop project you select. From there you can select which surfaces you want to import. Did you see your EG surface in the list of surfaces? If not then you may have not selected the right LDT project. If you did see it you should be able to select it by toggling on the check box for it and then it should import to your drawing.

[Anonymous]

The shift is not in location etc, it's in the Contours that I see. 

[Anonymous]

I selected the correct project but it would not allow me to select the "surface" option. I know that there's a .tin file as well as other information inside that project in LDD. What file will the "Surface" option read? .tin?

[Neilw_05]

Land Desktop surfaces are stored in the DTM folder under the project. Each surface is stored in it's own subfolder. The Import tool reads the data for each surface. As long as your surfaces are functional in Land Dektop the tool should work.

[Anonymous]

What's the surface's file called? I know there's a surface inside the dtm as I open the LDD project in LDD and I can see the surface.

[Neilw_05]

If you look in the surface folder you should see several files. The larger files contain the surface data. The files will vary according to what data you provided to build the surface (i.e. points, breaklines). The .tin file is the TIN. I don't know if you are able to extract the data from a .tin file as I think it is a proprietary binary format. You would have to use the LDT Import tool. I've never had a problem such as you are having. Have you tried it on another project? The tool will save you from having to open each LDT project and exporting the surfaces to a file.

[Neilw_05]

I've not used this command before Tim. Do you know if it equivalent to using the Land Desktop Import tool? Does the imported surface reflect the breaklines and points used in the original TIN?

[Neilw_05]

P.S. If the CreateSurfaceFromTin command is equivalent to the Land Desktop import tool, it might be a better solution since you don't have to wait for C3D to scan the LDT project for all it's other available data such as alignments and points. The downside is you have to import each surface one at a time so if there are many surfaces the LDT import tool might be better.

[troma]

Is there a horizontal or vertical shift?
Or is it just the contour smoothing that is different between LDD and C3D?

[troma]

We don't add 3D lines as breaklines.
We add them as drawing objects > Lines with the "Maintain edges" box checked.
We used to use this all the time when sent a surface in this format from outside.

[tcorey]

---

@Anonymous wrote:
I've not used this command before Tim. Do you know if it equivalent to using the Land Desktop Import tool? Does the imported surface reflect the breaklines and points used in the original TIN?

---

Yes, it is the same as using the Import Tool, except you just browse to the .tin file and import it. No other bs to deal with. No Project Path, Project, etc. to pick. No waiting, sometimes a long time, for C3D to read the project data and offer you the options.

The triangulation is preserved exactly as it is in LDD.