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Hi Everyone,

 

I have created a 'How-to' guidance for my colleagues for setting up project origins based on survey data with real world coordinates as per BIM Level 2 requirements (United Kingdom). I have read trough all the relevant VW Help sections and other forum topics and have also done lots of tests within the office. I would now need some proofread from experts to confirm that the process below is alright. I would very much appreciate any comments and notes:

 

"Please read this guidance carefully and follow the steps before you start drawing up anything in your project.

 

Importing Surveys (.dwg)
1.Open up a blank file
2. Choose ‘Import single DFX/DWG’
3. Leave all settings as default in the first three tabs within the import dialog box. Click on the last tab called Location and make sure that the first option is being chosen: “Center first import, align all subsequent imports (Recommended)”
4. Click OK
5. You should now see a light blue crosshair - called internal origin - in the middle of your survey as on the attached image

6. Make sure  that your co-ordinates shown on the survey are the same that you can see on your rulers The rulers are supposed to be shown around your drawing but if you cannot see them go to the upper right corner, click on the little black arrow and choose “Show rulers”. (Alternatively you can use the Stake tool with EN coordinates for the same purpose.)
7. Your drawing now has real-world coordinates and the internal origin has been placed in the centre of it. The internal origin is only used by the software for calculation. Please note that if your drawings are too far from the internal origin that can cause problems with OpenGL rendering and with calculation precision due to rounding errors.
8. If you have more than one .dwg survey file you can now import the rest into this file
9. Save your file and use it as a reference to your project file.

 

Troubleshooting: If the internal origin is shown somewhere far away from your survey then other objects must have been drawn somewhere else within the drawing. Hence the internal origin has been placed in the geometrical centre of all present objects. Identify the ‘pirate’ objects, get rid of them and go to Tools/Origin/Centre Drawing on Internal Origin. The internal origin should now be shown in the centre of the survey.


Setting Up the Project Origin Based on Survey

1. Open up your preferred SK or GA Template file
2. Make sure that your layers do not contain any drawings yet
3. Create a reference viewport by using the survey file you have created above and place it on to your preferred layer eg. “REF_Survey”
4. Go to Tools/Origin and choose Centre Drawing on Internal Origin
5. Check your co-ordinates again by your rulers as you did it previously
6. Your project file is now set to real world co-ordinates and is ready to proceed
7. Use rotated views and saved views to draw your building

 

Troubleshooting: If the internal origin is shown somewhere far away from your referenced survey then the same protocol applies as discussed in the previous troubleshooting section above

 

Please note that in Full BIM Projects (UK BIM level 2) the use of real-world coordinates is compulsory in order to provide the appropriate 3D environment for collaboration. "

Screen Shot 2018-02-14 at 14.38.46.png

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Hi Peter,

 

just one thing.

On 14.2.2018 at 5:47 PM, Peter Kovacs said:

Setting Up the Project Origin Based on Survey



3. Create a reference viewport by using the survey file you have created above and place it on to your preferred layer eg. “REF_Survey”
4. Go to Tools/Origin and choose Centre Drawing on Internal Origin
5. Check your co-ordinates again by your rulers as you did it previously

 

Here you rely on "center drawing" of the Referenced DLVP will position User Origin correctly.

That should normally work.

But If you did some changes like clean up work or clipping in the original DWG file before

referencing, it may fail. I normally copy and paste the User Origin Coordinates manually to my

Working File. At least one should check these.

 

And most times I don't want the survey file automatically centered by VW arbitrarily but want a

special point translated to the VW Origin. I do that by a test import (from File Origin) and by

reading and copying its coordinates and manually, to feed my User Origin position with these

Negative(!) values.

And I lately had a Problem doing so in VW 2018.

As it was so far that the Y value was larger than a million and appeared as a 5.123456789e06

(with eXX !), trying to set such a value to negative, lead to very unexpected behavior in VW 2018 !

Minus was recognized or or not after several attempts and User Origin setting got completly

corrupt.

It was not repairable and I had to throw that file away and start from scratch.

 

 

 

The other Problem that I have.

I do not really care about position and File Origin. I just do care because VW needs it that way.

But I care about my User Coordinates.

I want my Building positioned to the User Origin so that the Rulers and Coordinate Output is

centered on a special point at my Building (Building Axes Crossing)

If this would not be the case, I would lose the ability to all time check for position accuracy

of all my building parts by either OIP or snapping + status bar read out.

 

So what I really want is to assign a "Project Location" for a file that is only used for DWG

Exports and Imports, so that Imports get centered at a specific place at the File Origin

in VW and that they get Exported far away later again.

But that my "working" Coordinate System and Rulers stay centered around VW Origin.


So Project Location only calculated for Imports/Exports for DWG (and similar)

Any other Exports like STL for Printing or FBX/C4D for Visualization should ignore this

As I also want my Geometry centered around Internal Origin there too of course.

 

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Hi Zoomer,

 

Many thanks for your detailed answer, I've got to admit that I had to read through your post a few times to fully get your points but they definitely make sense. It took some time but I understand your approach. Interestingly the issue we have discussed here is not an isolated problem.  Other users on different platforms also get confused by the very same things. I have read into Revit and ArchiCad forum discussions about project origins. Both software works on pretty much the same basis in terms of coordinate systems as VW does, only the naming is different.

 

I think a proper guidance should really be issued on this topic by the VW guys. But it must be based on real-life scenarios because the general explanations for internal and user origins are rather vague and cause nothing but confusion.

 

As per my understanding there are two approaches. The first is to bring your stuff as close as possible to the internal origin and leave the user origin (0,0) where it is supposed be to get real-world coordinates. The second is when you centre your drawings in the internal origin and bring your user origin (0,0) to a known station point (=with coordinates). In the latter case your user origin and the software's internal origin can be the very same if you wish.

 

I think that the emphasis is being on the position of the internal origin though. If your drawings are too far from it then you might experience funny stuff later on. However it is also a fair point to mention that if you decide to use real world coordinates then your drawings can be incredibly far from your user origin and by those endlessly long numbers you will also be in trouble. It is truly fascinating how many ways you can mess things up.

Edited by Peter Kovacs

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I think for most people the recommended "center first" option is very ok.

 

And maybe the solution for keeping "ACAD far off" exchange compatibility AND

working around the coordinate center is a Custom Working Plane ?

 

But I am not sure if it will always work reliably with all tools and sub object modes (?)

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I'm always suspicious of that Center after Import option. Any experience welcome!

 

What does vwx use as the center of the imported objects?  Usually, vwx picks the center point of the extents of the selection or import objects, or the geometric center.  If two sets of objects are separately imported with the centering option turned on, say two survey data sets from different parts of a large site, do the two sets import correctly located relative to each other? Or do they end up overlayed/overlapped with their geometric centers at 000?

 

And, I often see unintended or improperly translated artifacts in the imports of dwg/dxf files.  Examples include text or other bits of objects far away from the geometry, or text with a miles long, empty boundary after the final character in the text string, or the center of a nearly flat arc located far from the arc perimeter and other geometry.  I suspect that these types of distant objects affect the centering in a way that defeats proper location of the imported geometry?

 

This kind of problem or suspicion would be eliminated if I know that the dwg files have some common reference point and direction that vwx will reliably read as the center. I can't know whether the dwg is properly constructed, mutually referenced, or imported without some way to test or compare the import to the source file.

 

I usually just import the several dwg files without centering into a separate vwx "shuttle" file, then reference some or all into a new vwx project file via a design layer viewport.

 

 

Edited by Benson Shaw

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