What's up with Origins, Autodesk?

[rkitect]

Our office is wandering into the realm of Navisworks and while the export from Revit feature leaves much to be desired, there is a much more interesting problem at hand that deals specifically with Revit.

In an attempt to have our Navisworks models align properly, I have began a template in Revit (one for RAC and one for RMEP) that has the origin marked with reference plane intersections. I did one template in MEP and one template in RAC. Here's the issue. Using link > Origin-to-Origin, the results are as follows:

RAC model linked into MEP


MEP model linked into RAC


Why would the origins be in different places in two fresh projects? You may be ready to ask me: "Why not just use Revit's shared coordinates tools?" The answer is that Navisworks does not acknowledge the shared coordinates system that Revit uses. This means that when I create an Architectural Navisworks model and a separate Mechanical Navisworks model, they will not line up.

Thoughts, ideas? This one is definitely frustrating.

[sbrown]

How did you find the origin in your templates. Make sure you really have revits 0,0,0 the easiest way to find it is to create a dwg with a cross hair at 0,0,0 then link that into revit origin to origin, that is your 0,0 in revit. my guess is its not right in one of the 2 templates.

[rkitect]

Wouldn't the easiest way to fin the origin in revit's project be to report the origin coordinates using the Tools>Report Shared Coordinates and the clicking an intersection? This is how I was finding the origin. I was under the impression that a project's shared coordinates are the same as the project coordinates until they are changed using the Aquire/Publish shared coordinates tool.

[bcgatti]

I've had the same problem with Navisworks inability to understand Revit's Shared Coordinates. Hopefully now that it is part of the AutoDesk Family it will "talk" better with this functionality.

Exported Revit items from files utilizing Shared Coordinates can "merge" into Navisworks at seemingly arbitrary locations. Our architectural model comes in in one spot, structural comes in at a different location, electrical at yet another location and so on.... All of these models utilize Shared Coordinates and line up perfectly when combined in any Revit session.

Also, since it can be so painful to try to "transform" an item in Navisworks (it would be nice to be able to "transform" an object by picking points instead of typing in offsets), on a few exports from Revit I have ended up exporting ACIS files from Revit - then importing them back into Revit so that I can move them to the "proper" location - then I export out to Navisworks format. This is painfully slow and it eliminates the ability to hide elements on an individual basis when you bring the exported Revit model into Navisworks.

I am completely self taught in Navisworks and I'm sure that I may be missing something as to how Revit and Navisworks interact and in the way that they interpret their origins.

If anyone has any feedback I would appreciate it.

Brett

[rkitect]

Scott,

Thanks, it appears that the Architectural Tamplate has a different 0,0 in shared coordinates from a fresh template, but MEP shares the the 0,0 point for shared and project coordinates from the get go.

RAC model imported into MEP:


I had the origin.dwg imported into both, so the presence of only 1 visible origin circle in the DWG indicates that they line up. The reference planes is the 0,0 point you get in the Default RAC template with the Report Shared Coordinates tool. Odd bug. It's a bit irritating that Revit ignores origin point so much considering how much trouble it causes with exports lining up correctly.

Thanks again,

[Teresa.Martin]

The Revit origin has always been an issue when working with other formats. One of the things to note is that the origin and 0,0,0 are not the same thing. In Autocad for years we assumed that the origin and 0,0,0 are in fact the same because 99% of the time they remained coincident. However they are actually two different things.

For example, if you do a little test by drawing two rectangles in Autocad and in one of the files move the rectangle and reset its base point (UCS>then move) to the lower left corner. It does not matter where you move it to.

If you bring in both of these files to Revit using the origin to origin option, you will see that the files do not line up in the project file.

That is because the WCS (world coordinate system) is what is being read, not the UCS. This is equivalent to the Origin in Revit vs. the 0,0,0 (shared coordinates).

I hope this helps!

Best regards,

[rkitect]

Interesting development. On a hunch, I opened the original default.rte template and imported the Origin.dwg into it. Lined up perfect and reported 0,0 at the center of the origin.dwg link. Looks lik someone had messed with the default template on this machine prior to me working on it. most likely used the Tools > Specify Shared coordinates tool to place the 0,0 shared coordinates at the RP intersection.

Thanks again for the help. This was one of those 'doh' moments.

[Teresa.Martin]

Interesting development. On a hunch, I opened the original default.rte template and imported the Origin.dwg into it. Lined up perfect and reported 0,0 at the center of the origin.dwg link. Looks lik someone had messed with the default template on this machine prior to me working on it. most likely used the Tools > Specify Shared coordinates tool to place the 0,0 shared coordinates at the RP intersection.

Thanks again for the help. This was one of those 'doh' moments.

Hey...it happens...We have all been there!

Best regards,