[Help] Revit Topo Surface does not to be created properly from imported Autocad 3D Face

[Seanc9XFAH]

Hi there, 

I have imported a dwg file that contains 3D Faces to Revit for creating a toposurface in Revit. However, the topo surface I have created by "Select import instance" tool in revit is not exactly same with the surface that is showing in Civil 3D. Please see the attached screenshot Figure 1 and Figure 2. 

The process I have done are

1. Extract 3D Face from TIN surface in civil 3d

2.Export the extracted 3D Face to AutoCad DWG file.

3. Link CAD in revit to the exported DWG file.

4. Create Topo Surface by "Select Import Instance" under "Create from Import" in Revit.

After I have done the steps above, I have got a funny topo surface which is completely unusable.

Also,  I have tried to create a TIN surface back from these extracted 3D Faces in Civil 3D and got the same surface which is unusable in revit. However, if I selected "Maintain edges from objects" during I create TIN surface from 3D surfaces in Civil 3D, and the surface is showing correctly in Civil 3D.  Please refer to attached Figure 3.

I am not sure whether there is a similar function of "Maintain edge from objects" exists in Revit.

Please help if anyone know how to sovle this.  Thanks in advance.

Figure 1: Civil 3D surface

Figure 2: Topo surface has been created by imported instance in Revit.

 

Figure 3 

 

 

Updates:

I have uploaded the original proposed surface that need to be imported to Revit here. Please let me know if anyone can show the surface in the dwg file correctly in  Revit.

 

[ToanDN]

Export the civil topo to a point txt or csv file, then create topo in Revit from that point file.

[barthbradley]

Why not use a building pad for that?  

...it's just a rectangle shape. Wouldn't be difficult to recreate with Building Pad.  Leave the Topo by Import Instance as is, and draw a BP on top of it.  Trace the one in the Imported CAD.  

[Seanc9XFAH]

Hi  @ToanDN ,

Thanks for your response. 

I have tried to export point files from surface in civil 3d and import the point file to revit. However, I have got the same problem I have. It also doesn't looks right. Please see the attached screenshot. Thank you.

 

[Seanc9XFAH]

Hi @barthbradley ,

Thanks for your response.

This is just an simple example. I do not really worry about the big hole in the centre of the surface, but more focus on the terrain elevations around the big rectanglar hole in the centre as I need to put landscape stuff in the correct level and locations, which are very relaying on a clear shaped ground.

This big hole in the centre site can be done easily as a building pad that you mentioned before. Sorry for I didnt explain this clearly before.

Please let me know if you know how to get the toposurface that is exatly same with the surface in my Civil 3D.

I have attached the point file that generated from Civil 3D surface here for your reference

.

[barthbradley]

I would suggest dropping the first three digits off both the x and y values (e.g. 8 1 1 and 4 2 7) .  Revit has a distance limit of 10 miles from the Internal Origin.  While you might be able to create it in Revit and move it closer to the Internal Origin, the translation may affect the point placement which could impact the accuracy of the translation. Better to just truncate values before translation.  

[Seanc9XFAH]

Hi @barthbradley,

Thanks for your suggestion.

I have tried to truncate values. However, I have still got the same problem.

[barthbradley]

FWIW: the translation on my end looks like your screenshot above.  I am seeing points placed at peculiar elevations relative to neighboring points.  Those point placements are derived from your CSV, so Revit is translating the CSV correctly. 

Got a screenshot of what you think it should look like?  

[Seanc9XFAH]

Hi @barthbradley ,

Could you post the screenshot of the topo surface that you have just tranlated by Revit from your end please? 

The ground that I need should be looks exactly same shape with the sreenshot that I took from CIVIL 3D.

[barthbradley]

Like the Civil 3D screenshot???  The one with the Building Pad-like indentation?  I have no idea how you get there with this point file.  

Anyways, here's the screenshot. 850 points. Looks like Revit might have missed 3. Looks like the CSV has 853. 

Contours omitted for clarity.

 

FWIW: Project Area=5266.10 SF and Surface Area=5796.60 SF.  

[Seanc9XFAH]

Hi @barthbradley ,

Yes, the Figure 1 Civil 3D surface is the proposed one I want it show up in Revit.

I have attached the civil 3d DWG file which cantains the surface here for you. I suspect that I may extracted the points in wrong way as you said those points cannot make the surface that I posted in Figure 1 Civil 3D surface.

Please let me know if I extracted point out of the proposed surface incorrectly.  Appreciate.

[Donovan.MerolaV2SXK]

Is there any update on this? As more & more clients wants the civil works to be done in revit. The link between Civil3d & Revit are crucial. I have the exact same issue. Surface is perfect in C3d, when imported to revit its totally unusable.

[tmCL9N6]

Use "Publish Surfaces" in civil 3d, and then link the topography in Revit.

That way you will have the exact same topography in both programs.

If you make any changes in civil 3d, publish the surface again, and reload link in Revit. 

[Donovan.MerolaV2SXK]

Thanks for your quick reply.

Yes we have been using this strategy but as soon as you have to issue all models ect to the client, who does not have access to ACC the link is broken & cannot find the surface. 

For some reason Revit does not pickup the 3d boundary lines from civil 3d when interpolating from the triangular 3d faces & also does not triangulate accurately where there are sudden drops of elevation levels for example retaining walls ect.

[tmCL9N6]

But when it cannot find the link, the topo should still be visible?

Revit does not respect feature lines or boundary lines, which makes it nearly impossible to make any usable surface.