Link Topography positioning

[pedro.hf.silva]

Hello friends, after exhaustively reviewing all Autodesk Knowledge Network articles and videos about this topic I would like to ask for a help with positioning "Linked Topography" surface in Revit. Here are the steps I followed without success:

Step 01 

Open topographic drawing in Civil3D and check if system coordinates are correctly configured. Everything looks good in drawing settings. Zone category and coordinate system correctly selected. Enabled aerial view and it is correctly superimposed with drawing. 

Step 2:

Identified coordination point within topographic base and inserted its values in drawing with text tool.

Step 3:

Open blank revit file, go to site view. "Link Cad" the topographic drawing with these options: Units Meters, uncheck correct lines off axis, positioning Center to Center, Align to view. Ok drawing appear unaligned but with correct north orientation. Move topographic drawing so that the coordination point gets aligned with Project Base Point and Survey Point. These two points were not moved nor the survey point unclipped. They still have zero values.

Step 4:

Acquire Topographic Drawing coordinates. Project Baase Point and Survey point acquires correct coordinates as identified in Civil3D file.

Step 5:

In Civil3D, export .shared surface from the same DWG file used in step 1.

Step 6:

In Revit, Link Topography selecting file generated in step 5. No erros messages or warnings about files not using same coordinates systems. They do. See end result below.

Link Topography aligns the geometric center of the surface with Revit´s Project Base Point / Survey Point. Though I tried to move them (the points) to check if the result would be different, the surface was positioned in the same spot.

What am I doing wrong?

This is very frustrating, the documentation Autodesk provides is absurdly superficial and elsewhere I look people never agree to each other's explanation.

Thanks!!

[syman2000]

When you link in your CAD center to center, did you move the CAD to end point of the project base point or you just leave it as is? AutoCAD has this system origin 0,0 to deal with. When you export it out, it will assume the survey point as your origin point. When you relink into Revit, this is why that surveyor is set to that origin point. It is a confusing process and a lot of people don't how it works.

Usually how I would approach it is to link center to center. Then move the CAD to where your project basepoint going to be (Corner of the property line is ideal). Rotate it if needed to match one of the properly line to align with one of the building face. Afterward you acquired the coordinate from the Civil 3d file. This will set the file to match the Civil 3d coordinate.

When you start exporting, by default it will go with project base point first unless you select Shared coordinate surveyor point. Hope this clarified a bit.

[pedro.hf.silva]

Hi @syman2000 thanks for your reply. I did exactly what you described you would do. I linked the cad file Center to Center then moved it to align the real world reference (bottom left corner of the property) with Project Base Point / Survey Point.

But then when I tried to "link topography" it didn't work.

[barthbradley]

How many  "Revit..." Named Sites do you have in your AutoCAD File (UCSMAN)?  

Can you post your AutoCAD File? 

[pedro.hf.silva]

Hello @barthbradley , that's new to me. I guess only one, I'm not familiarized with using multiple ucs in C3D. Here's the file.

[barthbradley]

No issues here.

...other than I missed the mark slightly in Revit.  😉

1. Link your DWG into Revit 

2. Un-clip the Survey Marker

3. Acquire Coordinates

4. Re-clip Survey Marker

...Maybe I'm missing something.  You wrote a lot of stuff.  Let me know.  

[barthbradley]

#5. Move  Project Base Point (optional)

[syman2000]

hmm...I am able to get the civil works with the Revit file. I am not sure what went wrong with your end. Once I remove CAD file and relink it, I use Auto - Shared Coordinates and it will pop in the right location. See the file attached and see if this is what you want to achieve.

[barthbradley]

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@pedro.hf.silva wrote:

I'm not familiarized with using multiple ucs in C3D.

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No? 

Sometimes, if you FULBAR (F*ck Up Linking Beyond All Repair); going into the UCSMAN and deleting the "Revit" Named UCS can help.