Project Coordinates, Shared Coordinates, and the new Survey Point

[tomnewsom]

I have never understood "Shared" coordinates. The terminology seems wrong. Shared? Shared with what? In what direction? How?

Here's what I do:

The 0,0,0 point of the survey sets the 0,0,0 point of my Revit file. Unless the surveyor is a complete idiot, this will be somewhere within the bounds of the site, or nearby. If it's not, then I edit and re-save the survey drawings (and re-distribute them to consultants)

If the survey drawings are oriented to True North, then I import them Origin-to-Origin into views that are also True North. If they are oriented Project North (more likely) then I insert them into views that are oriented Project North and then rotate True North from there.

My levels are set at absolute heights above sea level. I place a Sea Level datum in my project, on which I can place objects and give them exact elevations according to the survey. The toposurface also lives on this Level.

From then on, everything is done origin-to-origin. If it's 3D, it's done in a 3d view with the workplane set to Sea Level. It "just works" and as long as consultants don't move my drawings around when xref'ed (which I tell them not to!), nothing needs adjusting.

I have never used Shared coordinates. I don't even know what it does or how it works and every time I've tried I've failed. It is mysterious and opaque to me. This has not been a problem for me in 6 years of Revit use.

Is there a good reason why I should try again?

[Tommason]

How do I create multiple PBPs????

I'm setting up a new file which has three different buildings on a single site. As they are set out as a triangle, none have any kind of 90/45 degree relationship to one-another. My thinking was to set up these three buildings as separate Revit files and then link them into a Site Revit drawing. This way the site can have True North up the page and each building file can be drawn with separate grids and aligned neatly to the screen for easy drafting (without worrying which way is true north).

I have used this file setup for single buildings and have heard talk on forums that multiple locations can be set so that my three buildings can be referenced in at different angles and positions. I can't however find any information on exactly how to do this - any help would be much appreciated!

[clarkitekt]

Jeff,
Why can't this "hidden" internal coordinate system be exposed which I think woudl fix a lot of the confusion. It doesn't have to be editable, moveable, or constantly visible, but just visible in respect to the two other coordinates.

[clarkitekt]

I have also noticed that if the 0,0,0 coordinate of the survey is a really long distance from the site (the project I noticed this problem on, it is 370 miles from the site) acquire coordinates does not work.

Steps:
1. Linked in Survey at Center to Center (new Revit model with both Base and Survey point at Internal Coordinate).

2. The site comes in as expected with all drawing objects easily within 2 miles (with the 0,0,0 about 370 miles away)

3. Acquire coordinates from the Survey.

4. Survey Point stays exactly where it was with the Project Point and Internal Revit 0,0,0). Revit reports that the coordinates are shared though, that is not true.

Problems: If you then draw something at the surveys 0,0,0 and reload, Revit suddenly recognizes that point but moves the survey drawing to align with the internal Revit 0,0,0 point)

I thought I outsmarted it and manually moved the Survey Point to the Survey 0,0,0. This seemed to work ok except that there seems to be a bug where Level indicators aren't visible (anywhere, even if you make new ones). You can also make a section or callout and move it to the Survey Point and it disappears (no view cropping on).

[myBIMhero]

Wes - thanks for the very lengthy write up about coordinates. So far, I've gotten it to work, but when I export, I'm having problems. If I export using shared coordinates, the 0,0 comes out in the correct location (property line intersection) but the CAD plans come out to true north and the entire building is rotated - this is not good for the consultants. If I export using internal project, the CAD plans are correct at project north, but the 0,0 is now located at the "invisible" 3rd location that is the orignal location. I need the best of both worlds - 0,0 at the intersection AND project north drawings. Any ideas? Thanks.

[MetalliCAD]

I don't get the whole shared coordinates thing either. If I link in a file that does not line up, I move the link and call it a day. Before our projects get started we make sure all of the players are using the same origin point. Let's say structural created the grid in the proper origin, This gets linked to architectural who draws on top of it. No coordinate sharing involved. If I work with an outside firm, we send them our file and they link it in and draw on top of it, and vice versa. So what's the big deal? Just because you can? Am I missing somethng that will make life easier? From these threads I don't think so.

[Wes Macaulay]

When exporting to Shared Coordinates, you do get the building rotation along with the relocated 0,0 -- so you're right: you can't readily get the AutoCAD drawing exported with WCS 0,0 at the location of the Survey Point AND keep the Project North orientation in the resulting CAD export.

But you do get this: Revit creates a UCS called "REVIT60-Internal" (yes, this feature was added in Revit 6.0 years ago, and they've never changed the name of the UCS) and that UCS has a 0,0 set to the origin of Shared Coordinates.

[cborgen]

It exists -- you just can't see it in the view you're in. You may need to create a section off to the side that is extremely wide and has an infinite depth of view. In that view you may be able to find your Project Base Point.

Thanks to all the heavy-hitting posters here, reading through this thread has been pretty helpful. Just wanted to share a frustration that I just resolved in head-slapping fashion...couldn't find the survey point and project base point in plan, and realized that the crop boundary will hide them even if the view isn't cropped. So if you're struggling to find them, make sure your crop boundary is big enough. Not sure if I've noticed this behavior for any other element in Revit.

[dbaldacchino]

Hmmm in a plan view, if the sub-categories for the survey and project base points are enabled, the crop boundary has no effect on them. I tried multiple combinations of settings (annotation crop enabled/disabled, moved crop boundary so they lie outside, etc.) and they remained visible at all times.

[gbrowne]

In the UK we use Ordnance Survey info to set projects out, and often the 0,0 point is hundreds of miles from the site. I'm not sure what system is the norm in the US, etc.

So the simple question is:

Can I use shared coordinates on a project if the 0,0 point is outside the magic 1 mile radius?

I'm guessing you can't. I've worked on large projects where we had 20 very large sheds on a site and we 'faked it' by just moving the project to the O.S. coordinates, but didn't share it, and just placed the linked files in the site plan manually, and it worked well for producing setting out info. I'm about to start on an even bigger project and wanted to get a definitive answer before getting too far.