Project/Shared coordinates in Revit and the knot that slipped.

Project/Shared coordinates in Revit and the knot that slipped.

First some observations. And then to untie the knot.

Unclipping project base point and lowering it -10’ makes level 1 go to 10’. This Is -10’ from the site survey point.

If site point is left clipped and moved to the project point the project point will return to 0’-0”

If we want to set the shared coord to be 100’-0” then unpinning the site survey point and moving up to 100’. Reclipping and moving to align with level 1 will set the shared coord at that point to be 100’

This will set the project base point to be 90’.

Observed:

 Project base point displays in relation to site survey point.

Levels set to project coord will display its distance from the project base point. (not the actual elevation)

Levels set to site survey will display clipped relation to survey point.

Unclipping survey point allows the changing of values of that point. Level will remain. Moving the clipped survey point will change the level readout as distance from survey point.

Moving unpinned project base point closer or further from site point will change the value of the level reading the project cords. Moving pinned project base point will pull project away from survey point changing levels relating to shared cords.

Using specify cords at a point and selecting the level will move the survey point if it is pinned to those coordinates in relation to the project base point.

Using specify cords at a point and selecting the level with the survey point unpinned will leave its relationship to the project base point unchanged but will update  any levels showing survey cords and will change the project coord points value to relate back to the survey point.

Acquiring coordinates and base points. Observed

Unclipped

Before:

After:

Physical point doesn’t move. Both survey and project cords(elevations only) are updated with linked models

Clipped:

Survey point is moved(elevation) in order to create the updated position of the project base point.

The KNOT I created and how to untie it. Problems and solutions(hopefully)

So how best to solve this problem?

Structural started modeling first. Using a project base point of 650’ and a shared of 0’-0” so that the plan spots reported correctly to the engineers markups.  We were modeling from existing drawings that showed the civil elevations so that is how we started the model.

structural

architectural

I think I could easily bring in the arch file. Move it to line up and acquire coordinates, but this wouldn’t solve the problem of how our project coordinates relate. Also the arch cords have already been acquired (my bad)

This will require some moving of survey/project base points I think? If someone out there has comments on my madness please …drop me an email or post here.

Trial one: Project base point

Unpinning project base point to move up to -100’ which gives level one in my structural file a project level of 100’

This worked

Trial two: survey base point

Unpinned and moved up to 650’. Pinned and moved back down to align with level 1.

Now we can bring in the arch file “by shared coords” and our elevations will match theirs.

CANNOT  bring in origin to origin. I think it is because of Revit’s internal project coordinates. It will still bring in architectural at 100’. Which is still below 550’ that we are

How to get the Internal origins to align.(so you can use origin to origin again)

**p.s. you may just be better off using shared coords and not be so crazy about origin to origin like I am)

So the steps are:

Once the project and survey points match the file you are trying to link in origin to origin.

Link it in. if it comes in at a different elevation. then:

•     Unclip the project base point, move it the difference in its elevation and the linked file.
•    Select all of the levels move them in the same direction the same amount. (this maintains their project elevation reported from the distance of the project base point).
•        Move the CLIPPED survey point the same amount in the same direction. (this updates the project elevation in relation to the survey point).

Lesson Learned.

It is probably best to NEVER model your project starting out to the civil elevation (as your project base). It should be 0’-0” or 100’-0”. I had to wait until the architect started modeling to learn this lesson.  If you are confused modeling the existing drawings start with the project at 0’-0” and set your shared coords to the civil elevation (650’-0”) in the example above.

So this solved getting our model to line up origin to origin with arch when we started modeling first and had it all fubar. So what happens when civil is moving our models around on site and that site survey point isn’t in the correct place…I will leave that knot for them to untie.

Time for a motorcycle ride to clear my head and then on to Max and skin morphing or some Game of Thrones.

p.s i know most people are going to tell me quit being so crazy and just use Shared coordinates. but hey...my pain is your gain...i learned something, hope you did too.