Forums >> Revit Building >> Technical Support >> Origin to Origin

cadman6735

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Joined: Thu, Nov 13, 2008
148 Posts

I have always assume that when linking in Revit models (to be the same as Xrefs in AutoCAD) that if I use Origin to Origin that the 0,0,0 points would line up.  I have created a datum point in all my Revit model templates and assigned the center as my 0,0,0  so if a link gets moved I can just find the datum and put it back together again.  (Typicaly I use shared coordinates to link all my models so I really have never explored the Origin to Origin option.)

I am experimenting with linking in my models with Auto Origin to Origin and they all come in in abritraty places that make no sense to me.  I would have thought the 0,0,0 points would be the Origin and all would match up, similar to shared coordinates.

What does Revit consider the Origin to be?

Thanks

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WWHub

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Joined: Tue, May 16, 2006
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Revit models ...not model elements... are all located by way of coordinates.  Not a 2D 0,0,0 world like CAD. 

You can establish coordinates for a specific location in your project under the manage tab / project location / coordinates.  You can publish these coordinates to other linked files.

You can read more about this in several topics of your HELP.  Just search for coordinates.

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cadman6735

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Joined: Thu, Nov 13, 2008
148 Posts

Thanks WWHubb,

What does Revit consider the Origin to be?

Your responce has me a bit puzzled, AutoCAD does use a World "coordinate" system the same as I would think Revit would use the 0,0,0 point.  When inserting an element, group, CAD file, image or Revit Link it is inserted somewhere in space and if you use the "Specify Shared Coordinates" tool and select a point on an element you get a location relative to 0,0,0.  Which leads me to what does Revit consider as its origin when inserting a Revit link, is it the 0,0,0 point as the Insertion point?  When I use shared coordinates all works as I would think it should but using Auto Origin to Origin the z axsis lines up to 0 but x and y do not line up.

CAD is not 2D it is 3D 0,0,0 = (x,y,z) most CAD users only use CAD as a 2D system (This is part of the reason I think some CAD user have trouble moving to Revit, they are not used to thinking in 3D)

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"You can establish coordinates for a specific location in your project under the manage tab / project location / coordinates.  You can publish these coordinates to other linked files."

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Yes, this is using the "Shared Coordinate" option that I use as stated in my OP.

Sorry, pointing me to the help menu earked me a bit, if you don't mind can you find the answer for me in the help menu because I am unable to locate the exact answer I am looking for, which led me to posting my question here on RevitCity just to be pointed back to the help menu.

Thanks

-----------------------------------

• Ability is what you're capable of doing.
• Motivation determines what you do.
• Attitude determines how well you do it.

Quote by:  Holtz, Lou

• Life is all about the attitude

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WWHub

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Joined: Tue, May 16, 2006
13079 Posts

Follow this old tutorial:

http://www.revitcity.com/tutorials/finding_the_origin/

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cadman6735

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Joined: Thu, Nov 13, 2008
148 Posts

Thanks WWHub

Thanks for the link, that is the answer I was looking for.  I noticed it wasn't from the help menu either. (sorry sarcasim)

Yes, I had just figured this out myself by experamenting and was on my way to explain it to you for I thought you did not know the answer.  It appears that Revit does have a WCS and a UCS similar to AutoCAD.

The WCS is the origin to origin that Revit uses (the internal 0,0,0 that never changes) because no matter where I specify the 0,0,0 thru the  "Specify Shared Coordinates" when inserting a link via Origin to Origin or Manual Origin the Origin point is the internal 0,0,0 not the  "Specify Shared Coordinates" 0,0,0.  The  "Specify Shared Coordinates" will only work using insert via shared Coordinates.  This is very similar to changing the insertion point in AutoCAD when inserting xrefs.  the WCS 0,0,0 never really changes it uses a USC 0,0,0 as the inserstion point.

This is very useful information when working with links and when users move links and you have to break the shared coordinates in order to get the links and the model to line back up again after a user has saved the new coordinate of a moved link back to the model itself and everything gets out of wack.  I feel the help menu falls short on explaining this consept or I am unable to find the exact location where to find it.  (I am not that skilled yet at using this new online help menu.  I find it combersome).

WWHub thanks for your help, this new found knowledge will help me very much.

-----------------------------------

• Ability is what you're capable of doing.
• Motivation determines what you do.
• Attitude determines how well you do it.

Quote by:  Holtz, Lou

• Life is all about the attitude

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WWHub

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Joined: Tue, May 16, 2006
13079 Posts

So you have basically learned that the "UCS" is really un-important - right?  Shared coordinates are important and are how you should control your projects.  That is why I ponted you only to shared coordinates.

Only the project manager should control the shared coordinates and once a project is correctly linked, this issue should go away.  If your users are breaking these links, some retraining is appropriate.

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cadman6735

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Joined: Thu, Nov 13, 2008
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I defently learned that Origin to Origin does not come from the User defined 0,0,0 point. 

IMO, Shared Coordintates are the UCS (User Coordinate System), this is defined by the user Project Manager or in my case the CADBIM manager, me which I find to be very important.  But now knowing that the Origin to Origin is the WCS (World Coordinate System) which is internal and never changes, if I make sure to have this lined up at Project setup this will help with other issues I run into.  I can see a lot of posative benafits now that I understand the Origin to Origin concept.

Yes, training, training, training this is a must but there is always this one off accident from a new users (or this case an experianced user who thought they knew more than they really do) and thinks they are in CAD and can just move stuff to look as they need it to look.  These one offs cause a chain reaction of events that I have to chase and start thinking about another level of security to prevent the next accurance.  For me it is how do I fix it and fix it fast because once it is done it is done and the project becomes a stand still.

Yes, I see your point in pointing me to Shared Coordinates, my only frustration was that in my OP I stated that I use shared coordinates and I wanted to know something about Origin to Origin then you pointed me to the Help menu which is where I started then came here to be pointed right back again.  I felt you skated my question with a quick reflex answer without understanding my question and saying CAD is 2D had me wondering if you knew what I was talking about.  Your second post with the link was very helpfull.

I think all of this information is important.  Because if a user just imports without knowing the difference between import options, we spend our time wondering why things don't work the way we think they should.

WWHub, thanks for helping me understand Origin to Origin, I hope this will help others too.

Thanks again

Edited on: Tue, Jul 5, 2011 at 8:19:07 AM

-----------------------------------

• Ability is what you're capable of doing.
• Motivation determines what you do.
• Attitude determines how well you do it.

Quote by:  Holtz, Lou

• Life is all about the attitude

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