Origin to Origin not lining up

[donied]

I have a project with numerous files. All have shared coordinated setup and the project base point is at the same position in each file. If I link the files by shared coordinates or Project base point to project base point the all come in correctly.

I need to created a file where they are all linked origin to origin. Why you may ask not be happy with shared coordinates.

The reason i need origin to origin is when i export to IFC if the origin of each file is not aligned they don't line up in review software that only uses ifc.

How can i easily align the orign

Thanks

[Alfredo_Medina]

,,,and I assume that the project base point of your project is not at the same position as their origins?

[ennujozlagam]

....and you can check your own file by manage > coordinates > report shared coordinates, if  the same as other files. thanks

[RDAOU]

@donied

The origin to origin refers to the models' startup origin. If at one point you unclipped the project base point in any of the files and moved it (unclipped) then Origin 2 Origin linking will not work. This has nothing to do with shared coordinates and neither publish nor acquire will fix it

If you want to alone the origins, what you need to do is go into each file, unclip the project base point, right click it and select reset to startup.. Reclip it save and repeat for all files. Once done relink > align or set out where u need and republish coordinates (to reset shared coordinates)

once done, you can link with whatever method you desire and will always come same place where it should be

[Keith_Wilkinson]

My understanding and experience of this is that there are 3 coordinate systems - Survey, Project and Revit's own underlying system and it is the latter of these that defines the 'origin point' for origin to origin insertion. The only way to change this is to physically move the model within Revit (which as we know isn't the easiest of things to do once modelling is underway).

In theory the project base point can be anywhere depending on how your want your project dims to work but ideally they should be in an identical location for all consultants - moving this should have no effect on how the models load using origin to origin.

What we try to do on projects is issue the architectural model as early as possible to allow the other consultants to use this as a basis for their own. This model is linked using Origin to Origin and the model over the top. Shared coordinates are then set up when we have a suitable site survey. This gives us the ability to link in Revit by either Origin to Origin or by shared coordinates but more importantly it means that the models align correctly for federation when using IFC or NWC files.

There is some good information here for coordinate systems by Paul Aubin (there was a video as well but not sure if it's still available) http://paulaubin.com/_downloads/2015_RTC/Aubin_Revit_Coordinates_2016.pdf

[RDAOU]

@Keith_Wilkinson

(not sure if you intended to reply to the OP or me For a chitchat and opinion sharing)

if it is the latter here is what I think:

As long as what you described works for u then it's all good however I can't agree with the concept of 3 coordinates systems and what's associated them with...In REVIT and/or any other AEC platform there is 1 reference CS which is the WCS and and tthe  potential to host an infinite number of UCS (those of the linked/shared models) which are technically/mathematically a relative Euclidean (xyz axies) setout with respect to the WCS and the origin of that UCS is the startup origin of each model/file. The REVIT internal origin or the REVIT internal coordinat system is a myth...no! it is a hoax which someone started and many later bought (even some AUTODESK clever employees)

Respect to Aubin and all others (blogs, AU and almost everywhere Revit is discussed) all those conceptions and hypothesis on coordinate system is funny lol each has a concept of his own and non relates to what is actually in REvit. As a matter of fact since quite some time now I ve stopped reading any article which contains the keywords "shared parameters" "coordinate systems" "project relocate" and Project Base point and Survey Point"

edit: all known coordinate systems has specific definitions and function with respect to certain criteria...address the question "Define this coordinate system and clarify its functionality" to any party that claims or supports the existence of this imaginary/invisible/internal REVIT coordinate system and its unrevealable origin...so far no answer has been givin. It is mah physics and engineering 1+1 = 2 what exists can be defined and revealed and what doesn't 🙂 well I think you know the rest

[Keith_Wilkinson]

Bit of both - coordinate systems are often the source of problems so the more discussion to help with understanding the better I think.

The way I've understood it is that everything in Revit is stored with a definitive set of coordinates. After that both Shared and Project coordinates are generated simply by applying a conversion to these coordinates. Change either and the conversion changes but the underlying data about the objects location doesn't change.  

Its kinda similar to units - again my understanding is that the underlying system is Imperial and everything you see in metric is a conversion. 

You our have raised some questions in my head though so there's a few things I want to check tomorrow. 

[Keith_Wilkinson]

@RDAOU  :  I've recorded a quick screencast.  In it I've created a very basic model and then moved the location of the Survey base point so that it's away from it's initial starting position but still showing as 0,0,0.

Then using dynamo I've placed a marker at '0,0,0' - this point comes in as being the original starting point of the Basepoints.  I think this is a fairly clear demonstration that there are 3 coordinate systems at play but happy to hear another interpretation of this.

[RDAOU]

@Keith_Wilkinson

A 3 dimensional coordinate system, without going into the detailed definition of that system, should in principle have 3 axies (X/Y/Z) and an origin relative to which a point can be defined on that system.  When a coordinate system exists you should be able to define it's axies and you should be able to orient them. 

First system is the WCS where the X and Y are indicated when you select the survey point. The second is the UCS or the system relative the project, revealed when selecting the project base point (to clearly differentiate those two systems add an angle to true north)... Now if you believe in Dynamo which you used to define the 2nd 0,0,0 point (which you didn't need by the way) you should be able to write a script which can indicate the systems axies and their orientation. Or not? I have to say I can't and I haven't seen anyone so far who did. 

Moreover, if there are 3 systems, you should be able to define (using Dynamo or whatsoever tool) 3 origins with 0,0,0 each relative to a system. On your above attempt you managed 2 origins. Find the 3rd if it exists (noting that on a Cartesian grid any point may be mistaken for an origin...his shouldn't be the case since the we are talking of a system and not a relative point on a system)

While you are at it...in Revit there is a spot coordinate which reads Relative.

1. Use that to place a spot coordinate at the 0,0,0 point you placed using Dynamo. 
2. Then try to figure out the orientation of the X axis and Y axis of that 3rd system which you believe Dynamo located its origin 

Ps: if we are to continue the discussion I have to ask...are you familiar with surveying and triangulation? You might also want to share your REVIT sample file  so we both may be on the same channel.

[Keith_Wilkinson]

@RDAOU 

It's easy to define the axis - just plot 4 points - (0,0,0), (0,0,1), (0,1,0) and (1,0,0) as these are Cartesian coordinates they will define the X, Y and Z axis.  I don't see any problem with this at all.  The question you might ask is what coordinate system Dynamo is using to do this - as far as I'm concerned it's Revit's underlying system i.e. neither Survey nor Project.

To try and illustrate the point I've attached two files.  In terms of geometry both are identical and both have their Survey and Project Base points set to be identical.  However they have been constructed at different locations so when you import Origin to Origin they come in at different places.  If as you propose there are only two coordinate systems in play (Survey and Project) then you should in theory be able to get these 2 files to load in the same location using origin to origin without moving the geometry.

If you can do this I would very much like to know how it can be done as it would be incredibly useful in terms of coordination.

In term of your question about the spot coordinate it will report either the Survey Coordinates or the Project Coordinates (depending on how the tag is set up) - there is no option to report the underlying coordinate system.

p.s. yes I am familiar with surveying and triangulation but not sure it's directly relevant to this discussion.

[RDAOU]

@Keith_Wilkinson

1. There is no such thing as "as far as I am concerned"!!! It's either one knows for sure or one doesn't know...
2. The Survey point and Project base point are reference points not Origins; each is relative to one system. When the shared system is not actually shared, they do not come/align into the same position unless they are set out identically to the same shared system
3. What you had in your first screencast is a point placed by Dynamo at the Project's Startup Origin/Location or in other words the origin of the Project Coordinate system (this is one CS). The second, is that of the shared system (WCS) once you share it.
4. Triangulation is relevant in the sense where to locate/position a point you require either measurement and/or angles from 2 or more known points usually the origins of a CS. Not from an unknown origin. The two known origins are 1. That of the project (startup origin) and 2. that of the shared coordinate system. If there is 3 Origin...please do mark all 3 in a model, mark their axis and orient them to 3 different angles (in other word triangulate the 3rd missing Origin). Only then you can say that you have 3 distinct systems

I am going to assume for a second you are right and there is a 3rd origin for a third coordinate system...

1. What does it reference?
2. What is actually reference to it?
3. What difference would it make if that 3rd origin does not exist?

The following is a screencast based on your first screentcast and the dynamo script you used ... Two coordinate systems is all I see therein. If you see a 3rd which I missed out on please do highlight it. And please internal and invisible are not an answers

[RDAOU]

@Keith_Wilkinson

I have just checked the two test files  you uploaded...

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Keith.Wilkinson wrote:

To try and illustrate the point I've attached two files.  In terms of geometry both are identical and both have their Survey and Project Base points set to be identical.  However they have been constructed at different locations so when you import Origin to Origin they come in at different places.  If as you propose there are only two coordinate systems in play (Survey and Project) then you should in theory be able to get these 2 files to load in the same location using origin to origin without moving the geometry.

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You have been cheating 😛 (most probably unintentionally I assume lol) those two files do not have the identically set up origins (they are not set out identically) On file Test 2 you have relocated the Project Origin so how would you expect them to line up when line up when linked Origin to Origin.

The project base point "IS NEITHER THE PROJECT'S ORIGIN NOR THE ORIGIN OF ANY COORDINATE SYSTEM"... hence, regardless where you place the PBP, if you have tampered with the System's origin, the buildings will not line up. The project base point is just a reference point on 1 system nothing more nothing less.

I have recorded a screencast on those two files but it is taking forever to process. So I will just upload it tomorrow highlighting the reason why you are not able to line them up

[RDAOU]

Here is screencast on your test files 1 & 2 and my last reply to this post...

[Keith_Wilkinson]

In my original post on this thread I set out the need to issue a base model for other consultants to work around.  Without this there is no point of reference to locate the model - give 5 people the same sketch plan on a piece of paper and you will likely get them modeled in 5 different locations.  As your Screencast clearly shows there is absolutely no way to fix this without moving the model, which we have established on other threads is a pain in the **** to fix once the model is underway.  Making changes to either the Project Base Point or the Survey Base Point will make no difference to this.  the important point being though that in terms of setting a building out on site the project origin is irrelevant as we can simply control the coordinates with the 2 base points available to us.

This is the problem the original poster has.

I think though we are going to have to disagree about the coordinate systems - in terms of understanding of what is going on it is easiest for most people to consider it as 3 systems simply because you can have 3 points that give coordinates of 0,0,0.

Survey Base Point - defines the location of the project in the real world coordinate system.  Numbers are pretty big if you work in the UK but 0,0,0 still exists.  The building can easily be moved around the site if required by adjusting this system - there is no need to physically move the location of the building within the file - works best if a site file setup is used.

Project Base Point - local site coordinate system - provides more usable numbers on site.  Typically a ground floor grid location will be taken as the 0,0,0 point and coordinates, dims and levels can be referenced from that point.  Again this can be moved anywhere without moving the model geometry.

Revit Coordinate System - 0,0,0 point defined by 'Startup Location' or can be highlighted in the same way using the Dynamo script I used which placed a marker at 0,0,0.  This is the system used by Revit when using Origin to Origin insertion.  The coordinates of this system cannot be marked directly using spot coordinates (these will only report either the Project System or Survey System depending on how they have been set up).  Furthermore this system cannot be changed, if your model is in the wrong place you need to move if you want Origin to Origin insertion to work correctly.

3 systems, 3 origin points.  All 3 can have the same origin or all 3 can have different origins.

It's a shame you can't debate these issues without getting personal.  I know we've had some differences on here but I'm not doing this to try and antagonise it's simply to try and provide clarity for other users of the forum who may be struggling with understanding this issue as it's a really important one that can and does cause great frustration.  I think you're input on the forum as a whole has been great but if you don't wish to contribute any further then fair enough it would have been good to try and reach a conclusion though.

I wonder, is light a wave or a particle? 

[RDAOU]

From the very first beginning I told you if what you are doing works for you then all is good lol you insisted in discussing the topic. You want them to be 3 then 3 they are 🙂 and if 4, 5, 6 or even infinite brings more sense into it the infinite it shall be. In the end one can always define as much systems as he desires at any given point in space (I'm not arguing about that) however what is important is what makes sense and have true relevance. (And to be honest -don't take this one personal too- when someone can't explain something and tries to wrap things up with "as far as I am concerned" statement simply doesn't make sense to me)

Anyhow the screencasts above (using ur test files to clarify the misalignment and irrelevance of the PBP and SP) shall remain at ur disposal as well as others'. You are free to decide which and what makes sense.

PS: if it's the part related to cheating you consider personal, I meant that as a joke but if it offended you I take it back (although you did state the points were set out identically and they weren't)



Sent from my iPhone

[Keith_Wilkinson]

Outstanding.  Well done.

[Keith_Wilkinson]

In response to the OP's original question - Importing Origin to Origin within Revit is independent of the PBP and SBP.  Once the geometry is modeled there is nothing you can do to fix this without physically moving the geometry.  This scenario is all too common as many people / firms will just start modelling where they want and rely on Shared coordinates and Project Base Points to align things correctly.

We have come across this problem in the past when working with Vico where all models needed to be aligned Origin to Origin (not sure if it's still the case).  This was the main driver for us tightening up on how we work with other consultants and making sure we were all modelling relative to each other and the origin point.  Ultimately this makes everyone's lives easier.

[glenwalson7986]

Great post by the way.

So , the Origin - to - Origin point really doesn't ever move. Its just the distance that you drawing your building from it. Is that correct? I work for an MEP firm and we get Arch models and MEP models that  don't line up with each other at times. What causes this? and how can we correct it? 

Is it that the Architects move all of the building elements to a new location? 

When I find that the origin to origin doesn't line-up any longer a use the shared coordinates for the placement option. This seems to be easier to control. 

Any insight on the matter would be appreciated. 

Glen Walson

BIM Manager

Interface Engineering

[ToanDN]

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@glenwalson7986 wrote:

Great post by the way.

So , the Origin - to - Origin point really doesn't ever move. Its just the distance that you drawing your building from it. Is that correct? I work for an MEP firm and we get Arch models and MEP models that  don't line up with each other at times. What causes this? and how can we correct it? 

Is it that the Architects move all of the building elements to a new location? 

When I find that the origin to origin doesn't line-up any longer a use the shared coordinates for the placement option. This seems to be easier to control. 

Any insight on the matter would be appreciated. 

Glen Walson

BIM Manager

Interface Engineering

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The architect may have moved the Project Base Point.  If you don't have to deal with the original concern (IFC review software) then you don't need to be worried about Origin Point, just stick with Shared Coordinates and the models will line up always.

[Keith_Wilkinson]

When you start to build your MEP model if you link the Arch model into yours using Origin to Origin then this should never change.  It is VERY hard to move a model relative to this origin point so it's unlikely the Architect or anyone else would ever do this half way through a project, *unless* they start modelling all over again and if they did it would be courtesy to every other team member to model in the same location.

Obviously you can move survey point and porject base points but these will have no effect on the Origin to Origin import method.

If you are linking by Shared Coordinates and the building moves on the site then you will need to republish the shared coordinates to deal with this as the two models won't line up correctly again using this method until you do.

I'm just in the process of putting together a presentation on this - I'll provide a link once it's complete.

Cheers

K.