Project North and True North

[jamie santiago]

I am still confused with how "project north" and "true north" works, I am trying to rotate the property line parallel to where the north is pointing up. As I have read to other threads, i have to cretae the property line with the orientation in true view, in which i have done but when I rotate the line is either on the other side of my view, can anyone help me? thanks!

[Alfredo Medina]

Do not rotate the project, nor the site.

Project North is simply the orientation that is most comfortable for you to draw your project, either on paper or on the screen of a computer.

True North is the actual orientation of your project in relation to the North of the world. In Revit, plan views have a property, named as Orientation, which by default is set to Project North.

To provide a True North for your project, from a plan view, set this Orientation parameter to True North, and then go Manage > Position > Rotate True North, and provide an angle of deviation from the current Project North to the actual True North.

Now you have a correct position that will be useful in locating your model in a big site with other buildings, or to work with true shadows and natural lighting, etc. But, to continue working comfortably, you may set the Orientation parameter of the view back to Project North.

Makes sense? :)

[1966ford]

On the subject of True North & Project North, how does the Angle to True North value work in regards to linked files? I was doing some testing and after linking several files and sharing coordinates, I changed the Angle to True North in 1 of the linked files to 165 degrees where the others kept a value of 225 degrees. When I open the 'site' file that is set to 225 degrees, the liked 'consultant' file is shown rotated (this is the file set to 165 degrees). So even in a project north view a linked file with a different Angle to True North value will show as rotated. Is this expected?

[USMCBody]

In the past (and still sometimes) I don't understand the project 'orientation' stuff. Mostly because I just rely on what the Arch does as I'm currently at a consultant firm. So I don't really get into the meat of it. But the link below does seem to help me get my azimuth. It doesn't really talk about north per say, but it explains the coordinate systems Revit uses, which is typically were I'm really confused.

confused ?!?!?! I get that way too, but either way I hope this helps.... B-)

http://www.aecbytes.com/tipsandtricks/2010/issue54-revit1.html

[1966ford]

Thank you for the post USMC. I read through the article which was very useful. I just can't seem to find anything on the Angle to True North and how it impacts the orientation of linked files.

Imagine you are coordinating a very large project and there are a large number of files (consultants). Based on my testing, if the Angle to True North is not exact in every file, there will be issues when aligning and dimensioning between multiple files, generating elevations, etc. Is this somethng that has gone unoticed or am I just missing something? Inquiring minds want to know..

[Steve_Stafford]

Thank you for the post USMC. I read through the article which was very useful. I just can't seem to find anything on the Angle to True North and how it impacts the orientation of linked files.

Imagine you are coordinating a very large project and there are a large number of files (consultants). Based on my testing, if the Angle to True North is not exact in every file, there will be issues when aligning and dimensioning between multiple files, generating elevations, etc. Is this somethng that has gone unoticed or am I just missing something? Inquiring minds want to know..

If you initially link all other files using Auto - Origin to Origin then all the project files should be "aligned". That also assumes your project tracks like many do, architecture starts and then other trades get involved. The architecture team passes their model off to the other trades to begin their work, all using Auto - Origin to Origin for positioning.

If you define what True North is in your project file it should have no impact on their files other than showing them rotated like your project shows True North. If one of the other project team members uses Rotate True North in their project file it shouldn't change your file's relationship with theirs. The orientation of Project and True north is a "personal" relationship, your project only. If you start using Shared Coordinates then the rules change.

[1966ford]

If you start using Shared Coordinates then the rules change.

Thanks Steve for the additional input.

I am in a file marked Structural Consultant that has 3 files linked to it. It is the only file in the group with an angle to true north set to 168 degrees. Tthe view Orientation is set to Project North

When I open one of the linked files which have an angle to true north set to 225 degrees, the Structural Consultant file is showing (rotated) even though the plan view is also set to Project North

The files were all linked OTO and then shared coordinates were published to each linked file. Then the angle to true north in the Structural Consultant file was changed (for testing purposes, not that you would do that intentionally). A file with a different angle to true north value will display rotated and not project north. Trying to wrap my head around that logic…

Imagine you are coordinating a large project and there are a large number of files (consultants) that were received all generated from a template file you sent them. Based on my testing, if the Angle to True North is not exact in every file, there will be issues when aligning and dimensioning between multiple files, generating elevations (grid lines), etc. I’m wondering if this is something that has gone unnoticed because we just assume the consultants are doing things correctly. There is no mention of this anywhere.

[Steve_Stafford]

Command and Control... Somebody has to lead. Generally a project starts with an architect, not always but very often. Regardless the project file that starts sets everything else into motion. If we assume the architect starts, they create a project file and share that file with the other trades. They need to link the file using Origin to Origin before creating any geometry. This ensures that models align regardless of site considerations (including rotation).

If the architect gets more information and then defines what the real world orientation of their model is they can share the model with the other teams again. Each team can use Acquire Coordinates to "educate" their project file, learn what the new real world orientation is now. There can be only ONE, kind of like Highlander. You can't have different project files arguing about which orientation is the right one. It needs to be set in one place and then "acquired" by all the others.

All of this is irrelevant if nobody really needs to see this real world orientation or export to CAD using it. The use of Origin to Origin will keep everything aligned. One way a team can break this is when they decide to model the building oriented with the real site conditions, like aligning with an adjacent street or property line. Revit intends to let us "make it easy to draw" by drawing it on the page in an orientation that makes sense for the printed page without regard for the real site conditions. The True North setting allows us to choose when and which views need to show the real orientation.

I've written a lot of posts (http://revitoped.blogspot.com/2012/05/shared-coordinate-post-summary.html) on my blog about shared coordinates, perhaps one of them will help too?

[Revitaoist]

If you've done it right, your site plan will be oriented true north with the property lines tagged relative to true north and the building will be shown rotated, every other view will be project north with the building walls parallel to the view. In a 3D view the viewcube will reflect the building, so when you click 'front' the view rotates to the front door, and the compass on the viewcube will be rotated to true north.

[USMCBody]

Thanks Steve for the additional input.

I am in a file marked Structural Consultant that has 3 files linked to it. It is the only file in the group with an angle to true north set to 168 degrees. Tthe view Orientation is set to Project North

When I open one of the linked files which have an angle to true north set to 225 degrees, the Structural Consultant file is showing (rotated) even though the plan view is also set to Project North

The files were all linked OTO and then shared coordinates were published to each linked file. Then the angle to true north in the Structural Consultant file was changed (for testing purposes, not that you would do that intentionally). A file with a different angle to true north value will display rotated and not project north. Trying to wrap my head around that logic…

Imagine you are coordinating a large project and there are a large number of files (consultants) that were received all generated from a template file you sent them. Based on my testing, if the Angle to True North is not exact in every file, there will be issues when aligning and dimensioning between multiple files, generating elevations (grid lines), etc. I’m wondering if this is something that has gone unnoticed because we just assume the consultants are doing things correctly. There is no mention of this anywhere.

On the What is the logic of a sub consultant wanting to change north? Others said it in a more detailed way, but the basic version is if a sub Revit user of the prime, maybe it is the Civil guy, is feeling punch and really wants to correct the prime (Architect) he can. At least he would have the option to say my files are correct make yours like mine now.... Then everyone else would follow.

The unsaid thing here is probably no one really cares what the real north is unless it is your trade is legally responsible to know... Like the Civil guy. He is going to place the house on the site with the correct north set with some suggestions of house placement from the Arch. The Civil guy's stamp is responsible for making sure it fits all of the setbacks so he has final say. The Arch really only cares how well the house fits on the blueprint and most other designers that is really all they care about also. And I'm guessing for the most part the Civil file and the Arch files really don't mingle together... It's been a few years since I did civil drafting and they could mingle don't get me wrong, but they didn't then and I'm strongly guessing they still will not link together still.

Why does no one really care, because as far as I know in revit, there is no way to place a north arrow to 'link' to true north set up in Revit. They just place an annotation and rotate it to some where close to get the general idea, trying not to let others think it is the 'legal' north. It could make a big difference if someone lays out the site due to the north arrow the Arch is providing, which is a few degrees off of reality. I don't think anyone would really, but if you put it on the blueprints someone could, and probably has....

Further thinking the MEP may want an accurate north to get the estimated heating effects from the sun correct so I guess there is another person who may want to force the real north on the prime, but then again they may just keep a separate model for that so they don't make waves.

If nothing else think of it this way... Better to have the flexibility and not use it, rather than not have the flexibility and need it.

[USMCBody]

Man that was longer than Steve and I was trying for shorter... Sorry, once I get going it just spills out... B-)

[1966ford]

I think longer explanations are always better since there tends to be more detail and it usually answers more questions. Thank you guys for all the feedback.

My main concern is ensuring that all files are properly aligned (civil, etc) in order to get the most out of shared coordinates. Our firm wants to make use of sun studies, energy studies, spot coordinate information, and exports to Navisworks, so as you can see, if 1 rotation is slightly off, there is a domino effect.

[USMCBody]

The easiest thing to do is require a drafting contact that you can call and hash out thing's like this. Most drafters would be happy to actually use some 'advanced' features as we are all basically relearning the program every year. Not really so bad, but it feels something like that sometimes... Also have some contract to fall back on as not all companies would be happy to put in extra work, not that his problem has a lot of extra work, but maybe for some there is....

Look some at Steve's link also he provided in his previous post. Allot of content there. he was not kidding, and I'm only mentioning it because I missed it the first time. He made some words a hyperlink cauze I guess he is a smart one B-)... so look for the blue words in his post or just go here (where his hyperlink goes but in generic standout form instead...)

http://revitoped.blogspot.com/2012/05/shared-coordinate-post-summary.html

I'm not the expert in the subject matter here yet, but I believe the Acquire coordinate's and publish coordinate's would help transfer the north settings. I seem to remember someone saying otherwise, but I can't seem to track it down... My 3 young ones are sucking out my brain.... Or I'm just officially an old man now who can talk your head clean off if given the chance... B-)

Either way hope it helps, and please post your 'final' version of the events for future people looking for answers.

[Steve_Stafford]

... but I believe the Acquire coordinate's and publish coordinate's would help transfer the north settings. I seem to remember someone saying otherwise, but I can't seem to track it down...Acquire Coordinates (Publish is usually fine regardless) works unless the coordinates involved are very large then it gets unpredictable. For that reason I just use Specify Coordinates at Point. That always works. It just takes a bit more effort to determine what coordinate value to use. Like you wrote, always best to have someone to actually talk to when you are trying to coordinate files.

[tntdraftsol]

I have been reading these posts and it is a wealth of information, but I am still confused about what needs to be set and in what order. I am using Revit 2013 and here is what I have so far. I started modeling my building with no concern for true north or project north for that matter when I got through with my first floor I noticed that my South Elevation really needed to be my North Elevation (because I was modeling an existing building) so I used the Rotate Project North command and rotated project north 180 degrees, but my elevation view callouts did not go with them so I simply renamed them ( I fear that was a big mistake). I continued on with my model feeling like I had project North squared away and I would figure out True North later.

I complete the building model and use the Rotate True North tool to establish where true north is. I move my project base point and the survey point to a corner of the building that would correspond with a point from a Civil 3D drawing of the same area. I set up a master site plan Revit file to link my building model into and to eventually link other existing buildings into that are apart of the campus. Before I link in the one building I have already modeled I setup of my true north before hand and set the project base point and the survey point to correspond with the survey point from Civil 3D. I then link in the building model and I move/rotate/elevate the building model to were it needs to be in relation to true north. when I switch the orientation back to project north it does not look right. I know this is a lot, but I am desperately trying to avoid having to rebuild my model since it took me over a month to create. any help would be appreciated. If I have been unclear please allow to me to explain more. Thank you all for your help, I look forward to your replies.


Sincerely,

Mike

[Steve_Stafford]

...I started modeling my building with no concern for true north or project north for that matter... That's a good start, Revit is meant to let us draw the building without worrying about site orientation at first.


...when I got through with my first floor I noticed that my South Elevation really needed to be my North Elevation (because I was modeling an existing building) so I used the Rotate Project North command and rotated project north 180 degrees... This wasn't necessary because using Rotate True North would essentially resolve the orientation issue once it was used.


...but my elevation view callouts did not go with them so I simply renamed them ( I fear that was a big mistake). The elevations views are named North, South, East and West but they are just names. In the beginning of your work they could just as easily be elevation 1,2,3 and 4. Once you defined True North you could rename the views so they made more sense.


...I move my project base point and the survey point to a corner of the building that would correspond with a point from a Civil 3D drawing of the same area. Did you unpin them before moving them or leave them pinned? Did you enter any new coordinate information?


...I set up a master site plan Revit file to link my building model into... Before I link in the one building... I setup of my true north before hand and set the project base point and the survey point to correspond with the survey point from Civil 3D. Are you saying you did this in the Site model? When you create a site model the survey should be linked so that North is UP, using the WCS (World Coordinate System) of the survey file. In other words the survey is the "real world" and we bring it into a Revit project file. When you moved the project and survey points were they pinned or unpinned? Did you use Acquire Coordinates or Specify coordinates at Point?


...link in the building model ... move/rotate/elevate the building model to where it needs to be in relation to true north. This part is correct


...when I switch the orientation back to project north it does not look right. Are you still in the site model at this point or back in the building model?

If you want to follow through the steps based on exercises I did for a class at AU a few years ago you can DOWNLOAD IT (https://sites.google.com/a/aecadvantage.com/www/AB9114-1%20Shared%20Coordinates%20for%20Projects%20Big%20and%20Small%20-%20Steve%20Stafford.pdf?attredirects=0&d=1). If you want to mimic the campus situation you describe you need to follow the logic of the Large Project example. A single family home or isolated building would be possible using the Small Project process.

[tntdraftsol]

Did you unpin them before moving them or leave them pinned? Did you enter any new coordinate information?

I did unpin them before moving them, but I did not enter any new information for either of them.


Are you saying you did this in the Site model? When you create a site model the survey should be linked so that North is UP, using the WCS (World Coordinate System) of the survey file. In other words the survey is the "real world" and we bring it into a Revit project file. When you moved the project and survey points were they pinned or unpinned? Did you use Acquire Coordinates or Specify coordinates at Point?

I did do the setting of true north and the setting of the project base point/survey point in the Master site plan file. I did not have the Civil 3D drawing linked in at this time. The project and survey points were unpinned and I used Specify coordinates at Point to enter the information on the Survey point (I gave it the Northing, Easting & Elevation from the Civil 3D drawing.


Are you still in the site model at this point or back in the building model?

I am in the site model file when I switched back to project north. The callouts are right when I am in true north orientation, but not project north orientation.

Thank you for the AU PDF! I downloaded it and will follow the exercises. Thank you again Steve for your help!

Sincerely,

Mike

[Steve_Stafford]

Unpinning is good. Moving them pinned moves everything inside Revit so that wouldn't be ideal. Generally I don't find it necessary to use a project north in the site file. Project North is more relevant or useful in the building file so views (the building) are easier to put on paper orthogonally. I just leave the views in the site model oriented "up" (north). When you move/rotate/raise your building in the site model you are effectively putting it where it really goes on site. You can publish the coordinates of the site to the building at this point, the Publish Coordinates tool. Once you do that you'll find the building file understands the difference between true and project north without having to do anything about it directly in the building file like you did in the beginning. Do that with all the other buildings and then you can link one another into each other using Shared Coordinates and they "know" where they are in relation to one another "automatically". Pretty powerful once you get your head around it.

[USMCBody]

Steve will get you there, but I've found when I'm pulling out my hair using Revit, sometimes it is best to save a copy and play around with it and say (If I do this, it should do that)... And when it doesn't I say Why.... Sometimes the answer is I don't know and I undo and try something else, sometimes it is I that messed up, and sometimes it is a golden nugget... Hopfully it is the problem I was looking to solve, but it could be a window into better understanding Revit itself...

Food for thought anyway... B-)