Locating Survey Point when importing land survey

[dimitri.b]

I would like to know what the best practice is when importing a land survey. 

In the below image the topography/CAD file provided to me by the survey comes in on different levels. This makes sense because the topography contains contours which are a certain level above sea level or Australian Height Datum. I would like to know that when setting up the levels for the proposed project on the site, is it best practice to move the Project Base point up to the desired level of the building and then change the contours elevation base to be set to "survey point" (see below) and then draw layers at the desired height? 

I also read somewhere about the relocate project button, but the problem with using that is when you try to move the levels up the topography moves up as well? 

Could someone please shed some light on the best practice in dealing with this. 

Many thanks in advance.

Dimitri

[barthbradley]

Best practice is to Link the CAD into the Parent and move it to where it should be in relationship to the Parent Project and once positioned correctly, Acquire Coordinates of the Link.  So, if the Parent Project's Project Base Point represents Level 1 at 0'-0",  and that Level is 1000 feet above sea level in the real world, then the Link's sea level origin would be 1000 feet BELOW  the PBP.  

https://help.autodesk.com/view/RVT/2022/ENU/?guid=GUID-651EE8A9-FCFC-4999-91C6-4628FBCED902

[barthbradley]

Conversely, you could Link your Site in a New Project and call it your "Site" Project. Then Link your Building Project into this "Site" Project, move it to where is should be on the Site, and Publish Coordinates.  

https://help.autodesk.com/view/RVT/2023/ENU/?guid=GUID-92EB55C8-A5C3-46C9-90F1-50E4FAD1548C

[emodderman]

This video from Autodesk University had a good handout with steps to sort out something like this. It's always a bit tricky. 
https://www.autodesk.com/autodesk-university/class/Shared-Coordinates-Tales-Two-Bavarian-American-Ci...

[dimitri.b]

If I create a separate revit file for the site which contains the linked CAD file of the site topography etc 

When I link that site file into the separate building file I cannot see information for the CAD file which is linked into 

the site file if that makes sense

[emodderman]

Do you get the overlay warning from Revit?
https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/The-following-nest...

You've checked all the views and 3D and it isn't visible anywhere? Is anything cropped?

When you link the CAD into the first file, you'll want to make sure that the 'current view only' checkbox isn't checked, and make sure it's near the Revit Internal Origin...

[barthbradley]

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@dimitri.b wrote:

If I create a separate revit file for the site which contains the linked CAD file of the site topography etc 

When I link that site file into the separate building file I cannot see information for the CAD file which is linked into 

the site file if that makes sense

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What information can't you see?  

Sounds like you might be referring to the 2D Linework that is below the 3D Polyline-work that represents the topo contour intervals.  These polylines are what the Revit Toposuface is created from. The 2D linework is located at "sea level" in relationship to these polylines.   Am I reading the situation correctly?  If so, it sounds like simply adjusting the View Range to capture all the linework would resolve.  Have you tried setting Depth/Bottom to "Unlimited"?  

...or you could just lower the Toposurface - along with the CLIPPED Survey Point.  

[dimitri.b]

Yes I did, the survey point has also disappeared 

[barthbradley]

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@dimitri.b wrote:

Yes I did, the survey point has also disappeared 

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Go through this list of 33. I'm certain one of them applies.  

Can't see it in the view? Here's 33 reasons maybe why - Revit Forum

[dimitri.b]

Going back to my original question. 

I think I have set it up correctly. Could you please take a look at the attached file? 

I have referenced a "test" "building", into the site model. and used shared coordinates.

I have set the survey point to the sea level and made the levels relate to the survey point. So the actual 

building FFL reflects the correct height it would be. 

One other thing. I notice that when you use shared coordinates the PBP and survey point grey out which tells me they are shared. But how come there is an additional PBP for the site?  See below.

I have attached both the site file and the building file. 

[barthbradley]

Go into the View's VGOs and turn on the DWG in the Link. 

[barthbradley]

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@dimitri.b wrote:

Going back to my original question. 

I think I have set it up correctly. Could you please take a look at the attached file? 

"Original question"?  I thought the issue was that you couldn't see the DWG information from the Link.  That's what we've been working to resolve the last few posts. Regarding the "setup" overall, I would do it differently.  I wouldn't model the Building from 265000. I would model the Building from 0 and place the Link/Survey Point where it should be located IN RELATIONSHIP to the Building. 

Hopefully you can understand this screenshot. Note location of Parent Project's Internal Origin and Project Base Point. 

[dimitri.b]

So in your mark up have you placed the survey point at 0?

I suppose if I want my FFL to appear as 265m I could adjust the FFL to be relative to survey point and it will display it in that way? 

Interpreting what you're saying would be to model the building at level 0 then reference it into the site model or reference the site model into the building model? I understand there are shared coordinates and you can show the site in the building file and vice versa but I guess as a starting point I would want to determine what level I want my building at, so I would think you would reference the building into the site and locate where you think it best sits (or where the civil engineer decides) and then you can aquire those coordinates and reference the site into the building model. 

Soz, there are a few different questions here. But to summarise: 

1. Should the survey point be at sea level (where the flat 2d image is) 

2. If the building is modelled at level 0, do you reference the building into the site model

and then locate the building at where you want it at (eg 265m above sea level). Or from your mark up I am think youre suggesting the link is the site which is linked into the building model and locate it relative to the building? 

Thanks again for all your help over the past few months. 

[barthbradley]

Are you aware that Levels, Spot Elevations, Contour Labels have an "Elevation Base" Type Parameter.  If this parameter is set to Project Base Point, it will show the elevation in relation to the Project Base Point. If this parameter is set to Survey Point, it will show the elevation in relation to the Survey Point ORIGIN.  So, the bottom line is where the Elevation Base is located in relationship to the Building or Topo in the Project.  

[barthbradley]

Google for the PDF entitled "The Autodesk Revit Theory of Relativity: Understanding Shared Coordinates" by Paul Aubin.  I think it will help you wrap your brain around all of this.   

[dimitri.b]

Thanks for responding. Yes I am aware of it in fact my screenshot of it above shows the elevation to be set to survey point. So my understanding is you have set the survey point at sea level in order to achieve a spot elevation of 265m? 

[dimitri.b]

Ye he's good I watch his videos on Linkedin learning

[barthbradley · Accepted solution]

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@dimitri.b wrote:

Thanks for responding. Yes I am aware of it in fact my screenshot of it above shows the elevation to be set to survey point. So my understanding is you have set the survey point at sea level in order to achieve a spot elevation of 265m? 

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Just link the Survey Project into the Building Project, move the Link to the correct elevation and x,y location RELATIVE TO THE BULIDING and ACQUIRE COORDINATES.  Exactly what I said to do on the onset.  The Building Project's Survey Point Origin will relocate to the survey origin of the Survey Project. If that survey origin is at sea level in the Survey Project, then the Survey Point Origin will be at sea level in Building Project.   

[dimitri.b]

If you have already pressed publish coordinates can you go back and aquire coordinates. I noticed in Revit 21 prior to 21.1 there isnt a reset coordinates button? 

[barthbradley]

Published Coordinates from where?  From the Building Model to the Survey Model LINK or vice versa: from the Survey Project to the Building Project LINK?