Project Base Point and Survey Point vs Internal Origin best practice

[mpukas]

I've been around and around with this topic for years, trying to dial in a best practice for Project Base Point and Survey Point vs Internal Origin for linked files. I always have one Site file and at least one Building file, and now potentially a Survey file, that are all linked. My question is where is the best place to locate the Project Base Point and Survey Point in each file. 

In the Site file, the Survey Point is located at the Internal Origin, 0,0,0, which is where I place the site at one corner of the property boundary. In the Building file, the Project Base Point is located at one corner of the building, at the ground floor elevation, and at the Internal Origin. When I link the Building and Site files, the Survey Point is the same, the Project Base Point is the same, but the Internal Origin is different. 

Once the Site and Topo are set, they do not move, and the Survey Point does not move. When the Building file is linked in, it can be moved around, up and down, and the Project Base Point moves along with it accordingly. If, in the Building file, Project Base Point is at Internal Origin, then it will always be different between the Building and Site files. I always come back to the conclusion that is just the way it is, and not sweat it too much. 

One aspect of Internal Origin I do not understand is, in the Site file - or Survey file - when I rotate Project North, the Intern Origin rotates with it. In a True North view, Internal Origin is rotated to align with project north - not "up" in the view. In a Project North view, Internal Origin is "up" and True North is rotated accordingly. I'd assumed that since Internal Origin can't be moved, it would always be aligned to True North. 

One issue my method presents is when linking files, selecting by Internal Origin does not work, because the Internal Origin is the files is different. Shared Coordinates is the only method, and this only works when the coordinates are properly coordinated. And I often have issues with this. 

So, one question is should I have the Internal Origin located at the Survey Point for all project files? Or should I continue to keep the Survey Point in the Site file - and Survey file - at the Internal Origin, and in the Building File continue to keep the Project Base Point at the Internal Origin? I see pros and cons to both methods.

I do not like or agree with how Revit's coordinate system has been designed and implemented, but I have to adapt my method accordingly. 

[barthbradley]

No where did you mention Sharing Coordinates. Are you? If not, you're missing a critical step.  

https://help.autodesk.com/view/RVT/2024/ENU/?guid=GUID-B82147D6-7EAB-48AB-B0C3-3B160E2DCD17

Here, I think you would benefit greatly from reading Paul Aubin's "Theory Of Relativity". It was an immense to me in understanding Shared Coordinates. 

https://s3.us-east-2.amazonaws.com/pfacs.downloads/Conferences/Aubin_HAND_2015_RTC_Shared_Coordinate...

[mpukas]

Yes, I'm using shared coordinates. Sorry I failed to mention that, I assumed it was a given. 

I've not seen that paper by Paul. In glancing at it, I get most of he's written, but there is certainly more for me to gain in reading it completely. It was written prior to Internal Origin visibility being controllable. His point about making the origin for files in a project logical for THAT file is the conclusion that I've come to. 

Thanks for sharing that. 

[ToanDN]

Internal Origin plays no parts and should be ignored completely should you be using shared coordinates.

[Al_Alsahli]

🔧 Best Practice for Using the Internal Origin in Revit Coordination:

The internal origin point in Revit is especially useful when collaborating with other disciplines—like teams working in AutoCAD Plant 3D. Due to graphical limitations, those users typically model their elements near the origin (0,0,0) and maintain orthogonal alignment. In this case, it's important to use Revit’s internal origin as the insertion point, and make sure it aligns with their (0,0,0) coordinates.

📐 When linking their DWG into Revit:

• Create a level at the same elevation as the internal origin to ensure proper vertical placement.
• When using the coordination model in Revit, choose “Internal” as the reference point.
• Since Revit’s internal origin is rotated to match True North, their DWG model will be placed with accurate coordinates and rotation.

[RSomppi]

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@Al_Alsahli wrote:

The internal origin point in Revit is especially useful when collaborating with other disciplines

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I've never needed it. Access to the internal origin in Revit was not always available and is not needed unless best practices are not followed.

[Al_Alsahli]

me neither until you have georefrenced civil 3d and non georefrence plant 3d. so if you setup your internal as the plant 3d 0,0,0 it will be aligned automatically without any issue. 

[RSomppi]

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@Al_Alsahli wrote:

me neither until you have georefrenced civil 3d and non georefrence plant 3d. so if you setup your internal as the plant 3d 0,0,0 it will be aligned automatically without any issue. 

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I'm pretty sure that you cannot set-up the internal origin in Revit. Are you sure that you don't mean the survey base point?

[Al_Alsahli]

you can't not setup it but make sure the template by default has the 3 points aligned togather before georefrencing anything. To refrence it, first make sure your axes are done in the positive quadrant of these 3 points then make sure you coordinate with the teams that use software like Tekla, plant 3d etc to use thier 0,0,0 in the same position than your internal point to match your model. at this point, use manage tab - Coordinates drop down- select Specify Coordinates at point,

then pick your unping point and put the right coordinates.

this helped us specially when we insert models via insert - coordination model, since you have only 2 options, Shared and internal coordinates.

and as well linking dwg via link CAD