The Mechanical team received approval to start drawing before an architectural Revit model was available. The layout is essentially a big rectangle and rough dimensions were provided.
Now an architectural and structural model exists and there is a project base point that can be referenced.
In an ideal world (for reasons I don't fully understand), we will link in arch/struct/elec models using Positioning: Auto - Origin-to-Origin. I can get the models to line up fine if I use Auto - Project Base Point to Project Base Point, but I have had no luck if I do Origin to Origin regardless of how I adjust coordinates/PBP/SP in the mechanical model.
After quite a bit of reading through the forums, it appears as though there is no good way of adjusting coordinates/PBP/SP for what has been drawn so that when we link in the arch/struc/elec we can position Origin-to-origin without actually shifting the drawn elements to a new location. No amount of acquiring coordinates or moving PBP/SP actually moves the model as it relates to the (hidden) origin.
I feel like I am at an understanding of about 85% with this -- so my apologies if I misspeak. I guess I am just looking for confirmation on this so I don't spin my wheels.
Unfortunately, I cannot share the model or any screenshots for this particular job so I’ll try and be as descriptive as I can.
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General Mech Model Info:
Rectangular in shape with Grid Lines (A through K) and (1 through 5)
PBP Visual Location: Grids K-5
SP Visual Location: Grids K-5
PBP Shared Site Info:
N/S: 0'0"
E/W: 0'0"
Elev: 0'0"
Angle to True North: 0.00
Survey Point - Internal
Shared Site:
N/S: 0'0"
E/W: 0'0"
Elev: 0'0"
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Attempt 1:
From Mechanical Model
A)
Insert/link Arch model using Auto - Origin-to-Origin option.
B)
The architectural model's K-5 grid intersection appears at mechanical model's C-2 -- which is where the Mech's PBP goes when we "Move to Startup Location", aka Internal Origin:
N/S: 95' 10 173/256"
E/W: -251' 6 247/256"
Elev: 0'0"
Angle to True North: 0.00
C)
Unlink/Remove Arch model
D)
Select PBP Shared Site (still clipped) and set to the following values obtained from "Move to Startup Location":
N/S: 95' 10 173/256"
E/W: -251' 6 247/256"
Elev: 0'0"
Angle to True North: 0.00
Survey Point - Internal Remains at:
N/S: 0'0"
E/W: 0'0"
Elev: 0'0"
(Note, if I set/acquire coordinates from the ARCH model, the survey point moves to the C2 location and is 0'd out, and when I move my PBP to the SP, it gets 0'd out as well – I suppose this is expected behavior with the understanding that these are just reference points)
The idea with this step is that I thought I was moving my model and the PBP to the Internal Origin because it remained clipped.
E)
When I now link in the Arch model using Auto - Origin-to-Origin option, the arch model's K-5 location is again inserted at the mechanical model's C-2.
Again, with the understanding that Revit's internal origin never moves, I thought by moving my project base point (while clipped) to the coordinates obtained from "Move to Startup Location", that I would be moving my PBP and the physical model to the internal origin so that I could link in my arch model using Origin to Origin and have them be lined up -- but it does not.
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Dirty method:
If I instead move the PBP unclipped, and then select all the drawn elements/equipment and move them over using grid line K-5 as my start point and C-2 as my destination, and THEN link in the Arch model using Auto - Origin-to-Origin, everything is lined up. However, I get all kinds of errors about duct/pipe having been modified to be in the opposite direction causing connections to become invalid.
Quick note: I just found a link to David Baldacchino's "Navigating Through the Storm Using Coordinate Systems in Revit" video. I won't have an opportunity to watch it until over the weekend, but I've heard it's helped a lot of people understand the coordinate system in Revit.
