Project Location

[MikeJarosz]

What, if any, relationship is there between project location and the project base point? I acquired coordinates from the Civil 3D Acad file. That left the project location at the default, which I believe is Revit HQ in Waltham Mass. So I then reset my project location to a point in NYC using the built-in Google Map. This had no effect on the project base point, so I guessed that there is no relationship between the two. Is there any benefit to get the two points to coincide? The project base point is in decimal feet and the project location is in latitude/longitude. That's not easy to deal with.

I expect to do energy and shadow analysis, so I understand the benefit of the project location. What I cannot figure out if there should be a link between the two points.

[cliff collins]

Have a look here--long, but well worth it. and you can use it later as a reference.

http://paulaubin.com/_downloads/2011_AU/Papers/AB3733_Aubin_SharedCoord.pdf

[dhurtubise]

There i no link.
Shared Coordinates gives you the actual world positioning and the Project Coordinates gives you the ability to set the origin at a specific place... in a nutshell :)

[MikeJarosz]

Thanks. Reading and rereading the shared cords documentation out there lead me to suspect there was no connection. However, most of that documentation is clear as an 8" CMU.

A while back, there was a book "The Inmates Are Running the Asylum" that argued that programs and their documentation are written to satisfy....the programmers, not the user. That certainly applies to the shared coordinates docs!!!

We need a new book "Shared Coordinates for Dummies"

[damon.sidel]

I don't see any benefit to having the Project Base Point have an explicit relationship to the Location. I will speculate now:

There is an "internal origin: a "true" 0,0,0. I call this "true" because if you import information (Automatic origin-to-origin) from ACAD or another cad software with 0,0,0 marked, this is where it ends up. And when you export, this is the important point, too. My guess would be that the Location of a Revit project is actually saying this internal origin point is equivalent to the chosen latitude and longitude. And in fact, I think the Project Base and Survey points are relative to this internal origin, too. I'm very aware of this internal origin because we do a lot of work between cad software like Rhino3d.

- Project Base Point = nice point on/near the building that can be called a relative origin. The orientation of this is along some useful axes of the building. Personally, I like to leave this as-is so it coincides with the internal origin for translating the model between Revit and Rhino3d.

- Shared Point = the relationship between the Project Base Point position and orientation to a known position and north on/near the site, usually from the survey.

- Location = where the building lives on planet Earth. Since this is used for energy and solar analysis, it doesn't even need to be all that precise.

That's my take on all the origins.

[MikeJarosz]

Thanks. This was my inner feeling, but it's always good to get confirmation.

[tntdraftsol]

FYI Steve Stafford's blog (http://revitoped.blogspot.com/2012/05/shared-coordinate-post-summary.html) has some good info about shared coordinate systems as well.

[patricks]

I will echo that there is no relationship between Project Location and the Project Base Point. On a recent project I set the PBP to the corner of an existing building, and rather than have dimensions all over my site layout plan, I placed Spot Coordinates, which showed an N/S dimension and an E/W dimension (like X and Y coordinates) relative to the corner of that existing building.

[CAtDiva]

I will echo that there is no relationship between Project Location and the Project Base Point. On a recent project I set the PBP to the corner of an existing building, and rather than have dimensions all over my site layout plan, I placed Spot Coordinates, which showed an N/S dimension and an E/W dimension (like X and Y coordinates) relative to the corner of that existing building.

Nice! I really like that approach.