Trouble with origin point(s)

[alfie hope]

So my office has been having trouble with models sited away from the origin point - elements such as walls do not behave correctly.

We found the following link which 'sort of' explains that there are TWO different origins.

http://www.vectorlab.info/index.php?title=Absolute_Origin

A coordinate origin - as set by us VW users, and a VW origin (which cannot be changed) as set by vectorworks - for coordinating/calculating etc (i.e the center of the page when opening a new file).

The way in which we have been setting up projects involves setting the centre of the page as the coordinate origin and placing the site survey and building as required away from there - but it now looks as if this is where we should be placing our model in the centre of the page upon opening a new file and setting the origin away from there.

So basically it appears that if you put your model info away from the VW page origin it causes problems.

Our experiments with this so far have proved this theory and we've recently subscribed to service select who were unaware of these 2 different origins, but who are inclined to agree with this article so far.

Has anybody else had these problems? Can anybody offer any advice?

[ray isaacs]

alphie,

because i work with gis people, i try to work with world coordinates as much as possible, meaning that we were many kilometers away from the origin. as early as 2010, we discovered that many 3d functions do not work when you get far from the origin. this was confirmed by vw. so we had to reset the origin to somewhere within the model.

i've never heard of the second, vw origin that you are describing. this sounds like a related detail. it would be good if someone from vw would explain all of this. and also explain how geo-referencing works, given these problems. i am told that geo-referencing is possible despite the coordinate problem. but my gis people do not see how it works and therefore do not trust it.

vw, can you please clarify this?

[Kevin McAllister]

Alfie,

What version of Vectorworks are you using? This used to be true in older versions. The 3D working plane origin was separate from the 2D "page" origin. It often caused problems. I tested it in VW2013 and it doesn't seem to be true any longer. It probably hasn't been for a few versions.

In newer versions I have seen two origins occur when a DWG is imported directly into your working file. Everything seems fine but if you export you'll find a discrepancy. In my case it showed up when I sent my file to Cinema 4D. Things that were centred at the origin in my Vectorworks file were offset from the origin in Cinema 4D. My distributor confirmed that this can happen.

In my experience I would recommend never moving the origin and never importing a DWG directly into your working file. Probably doesn't help in your case. Perhaps you can build your model in a separate file where its close to the origin and reference it in. I don't know if this will solve your issue though.

Kevin

[Dieter @ DWorks]

There are indeed 2 origin points, the internal one wich can't be moved and the user defined. The main reason for the problem is that some functions use the internal origin while others the user origin. Another reason is just that the numbers in the calculations VW have to make are becomming too high. So there is only one option to avoid any problems and the number one golden rule: never move the origin!

[Diamond]

Hi Alfie,

I am working on a project now that is using a 3D survey on extremely challenging terrain. The survey has a reference marker that is kilometres away from the building works. The only thing to do is use a local origin to stop VW acting oddly.

We agreed on a wall edge of an existing building with all consultants and set out our building grids on this point as our local origin (vs the world origin). From this we (the architects) set out the grids for the three locations of new works.

But this is where the plot thickens. One of the locations is down a cliff 200 metres in elevation below the main works. It was very important that all drawings were using the same local origin as the set out of part of the works was only possible using GPS.

Next time I would use GIS, but some of he settings did not match up with VW (I need to follow this up and maybe file a bug). And the problems caused by not using GIS and the inaccuracies caused by the curvature of the earth are a story for another day.

Put briefly, don't move the local origin if you can help it, but there are times when you have no choice.