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Is Rotating Project North ever a bad idea?

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    Is Rotating Project North ever a bad idea?

    I am working on an existing building. I have modeled the entire building the way the existing drawings were laid out, which is east-west (long ways). For the new phase of our project, we want to show the building on the plan sheets north-south direction. Should I just rotate the project north 90 degrees, or is that a bad idea? The other option is to just rotate the views, correct?

    Revit 2016

    #2
    Well Revit was originally conceived with the notion of modeling to Project North at the outset and then Rotating True North secondarily. The Rotate Project North tool was added much much later, in response to the continuing legacy of people not doing it the way they envisioned it being done. I suppose they just never did an adequate job of explaining it back then and still don't today.

    The problem with Rotate Project North is that it is equal to having you select EVERY 3D element AND EVERY annotation applied to EVERY view at the SAME TIME and using the Rotate tool. If you've ever tried to do that you know it isn't actually possible. You can rotate 3D elements easily enough but all the related 2D annotation...well mileage will vary.

    So...yes you can use it and you may even find it works pretty well but you WILL have to review every little aspect of your model and every view/sheet to make sure that nothing is amiss.

    For every future project, start with a specific Project North orientation, make it easy to draw. Then use Rotate True North. That tool is a slight of hand trick that doesn't actually change anything other than the orientation of what we see in a given view.

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      #3
      Steve, thanks for replying with that detailed information. I really appreciate it.

      My other question is, what happens when we link with other discipline's models? Let's say, Structural rotates project north and Arch'l only rotates views. They will not line up correctly, right? Is this an issue that has to be addressed at the absolute beginning of a project, or can it be "fixed" with other tools?

      Thanks!

      Originally posted by Steve_Stafford View Post
      Well Revit was originally conceived with the notion of modeling to Project North at the outset and then Rotating True North secondarily. The Rotate Project North tool was added much much later, in response to the continuing legacy of people not doing it the way they envisioned it being done. I suppose they just never did an adequate job of explaining it back then and still don't today.

      The problem with Rotate Project North is that it is equal to having you select EVERY 3D element AND EVERY annotation applied to EVERY view at the SAME TIME and using the Rotate tool. If you've ever tried to do that you know it isn't actually possible. You can rotate 3D elements easily enough but all the related 2D annotation...well mileage will vary.

      So...yes you can use it and you may even find it works pretty well but you WILL have to review every little aspect of your model and every view/sheet to make sure that nothing is amiss.

      For every future project, start with a specific Project North orientation, make it easy to draw. Then use Rotate True North. That tool is a slight of hand trick that doesn't actually change anything other than the orientation of what we see in a given view.

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        #4
        Yes, it will affect the other trades. If you do it, they'll have to do it. They'll find your model rotated the next time your link is refreshed in their model. Fixing the model alignment issues that occur as a result usually involves some tears before things are back in alignment.

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          #5
          If at all possible, I'd suggest you draw the new portion as a linked model. At that stage you can have it rotated differently. As long as you rotate true north and position survey correctly it would work without hitches. If you cannot simply perform a linked model arrangement for the new portion (e.g. some walls need to join onto existing) then I'd suggest you use scope boxes which you rotate to the alternative project north - that way you can set a view (or even many at once) to a scope box and it rotates the view (not the model and all related stuff). Those two ideas are the least problematic, first one preferred due to less work. The second is a good choice if the building is at various different angles (think something like the Pentagon, with each wing having its own scope box).

          It should also solve any consultant models. Learn to use survey coordinates and true-north rotation correctly. That way any consultant could choose whatever project rotation and project base point they wish. All would still link into each other in the correct positions and rotations. As Steve's mentioned, True North and Survey Coordinates is way too under-emphasized - it's the best way to solve many of these issues. And I personally believe none of the courses do enough to train users how to properly use them.

          The only time I'd even consider a project north rotation is when the existing model is still at the start stages. Very few views and annotations done. Else you're sure to loose stuff like tags, dims, etc. Text and whatnot are definitely going to move to positions where they overlap (either each other or linework / model elements). You'll find that just going through all sheets / views to see what went wrong becomes a task equivalent to redoing all of them.

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            #6
            Thanks for your thoughts!

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              #7
              Originally posted by Steve_Stafford View Post
              Well Revit was originally conceived with the notion of modeling to Project North at the outset and then Rotating True North secondarily. The Rotate Project North tool was added much much later, in response to the continuing legacy of people not doing it the way they envisioned it being done. I suppose they just never did an adequate job of explaining it back then and still don't today.
              THAT is a helpful tip.

              For whatever reason, I have always modeled in True North and rotated - because that seemed logical to me, and because most projects start on top of a survey and most surveys are drawn to true north.

              And yes it's just a total mess what it does to lots of things when you rotate these things after the project has been detailed. All sorts of objects just flip out.

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                #8
                I've always seen it as a logical progression.
                Model orthogonally, or as close to as can for most of the building, in project north.
                Then I rotate true north mainly for correct shadows for planning requirements, and any view that might require it, such as one particular project which required the site plans to be shown in true north, as orthogonal project north was too wide for the A1.
                Motorbike riding is one long bezier curve

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                  #9
                  Originally posted by bt.comm View Post
                  ...For whatever reason, I have always modeled in True North and rotated - because that seemed logical to me, and because most projects start on top of a survey and most surveys are drawn to true north...
                  Well...the assumption is that your client hires you and you ask if they have a survey. They say, "What's that?" or "Yeah, here's a 8.5"x11" sheet of paper" or "Yeah, here's the survey from 1908"... The bottom line is very often that initial survey isn't entirely trustworthy...unless your client has been there done this before and they walk in with a new survey to start with...if so they are KEEPERS!

                  Starting off with Project North as your default assumption/behavior/habit avoids the whole conflict..."can I trust the survey yet or not?" Since Revit is designed to make the transition from Project North to True North VERY EASY, that's the best path to take.

                  If I remember my trivia correctly...Rotate Project North was a rogue developer project (name withheld to protect the guilty) that was slipped into the product and ultimately had to continue to exist because it existed. It also had to be reworked because it didn't adequately take into account for some other new features that were planned to be part of the new release, at the time. It's been tweaked again in the 2017 release...

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                    #10
                    Yep, it should probably be categorized as an UN-necessary evil. The "project north" is definitely a misnomer - it should rather be called something like Gird-line Orientation, or Building main axis orientation. It's got nothing to do with where the north pole is. It is similar to the troubles caused by the naming of he coordinate systems in AutoCAD (i.e. "World Coordinate System" is actually "Drawing Coordinate System", and a "User Coordinate System" is what you'd use to simulate a "Survey Coordinate System" instead of attempting to draw everything miles from the beacon's location at some arb angle - sure way to introduce floating point errors and non-perpendicular corners).

                    Personally, the TN idea works well, though I tend to even split out the survey as a "Site-model" linked into the building model - at least until a final survey is done. Usually the best you get at the start of a project is the cadastral site boundaries (that's if the local council can "find" it) and a sort-of idea where the falls of the site goes (basically similar to what you'd be able to get from google earth).

                    Now arranging your building onto that to start off with and then attempting to rotate it afterwards when a "real" survey is done, is a sure way to screw up your model and any associative annotations. With the linked idea it's very easy to simply move / rotate the building around in the site model, or move/rotate the site around in the building model while you're attempting to find the best orientation / positioning / level for it - and you're not affecting any drawings. If you then also use TN and Survey positions, including shared coordinates - a move / rotation of the link (either the building link in the site model or the site link in the building model) would update the survey coordinates in the other as well - so your true north and survey levels / grid coordinates update accordingly. And that all while any annotations you've made stay put on their original positions in all views.

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