Coordinate question

[Jonathan3891]

I've been reading up on Advance Steel best practices, and it says that you should start your model at 0,0. 

We always model structures at their real world coordinates.

What is the best workflow for this scerano? How can I model at 0,0 but have everything fit together in navisworks with the other diciplines?

[acbsdesign]

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@Jonathan3891 wrote:

I've been reading up on Advance Steel best practices, and it says that you should start your model at 0,0. 

We always model structures at their real world coordinates.

What is the best workflow for this scerano? How can I model at 0,0 but have everything fit together in navisworks with the other diciplines?

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Hi,

Just did a building that is pre-engineered and fabricated by others  (large size company well established) and I had to coordinate new steel within it in Navisworks,  their 0,0,0 was at the top left corner, at the first main grid lines intersection.

So it was consistent with how we usually start the structural frame. Top left corner, letters going down, numbers going right.

There is BIM certification that may help, if you hear about something US based please put it here.

Regards.

[markhubrich]

I usually apply a transform or use a shared coordinate system. The first job where I experienced the negative effects opened my eyes as to why you want to be close to 0,0,0. The engineer had his model zero many miles away. They kept the survey coordinate location and my model file was instant bloat. Everything does math related to 0,0,0. When all your coordinates of objects have values that show like"6.0640078e+44" then that's too far.

I'd say it really depends on your purpose. In Navis, once you apply transform, it stays. If the models get updated the transform holds. My workflow is to get arch revit model into navis as my base. I then append my very minimal model for the purpose of alignment. That is when I see how far from 0,0,0 I am. If my model requires sharing with 3rd parties for BIM coordination then I will move my model around so BIM coordinator doesn't complain. They don't want to deal with applying transform to every trade. 

If any Navis work is in house then I'll usually place column line intersection A/1 or whatever at 0,0,0 at el.+0'-0". If you then receive  files from other trades then most times you can simply match the transform you gave the arch Revit model to align to your model. 

This is only a small example of scenarios. If you add point cloud data into this mix, well, ask the provider of the data to align to either your coordinates or the Revit model. For me, I have not mastered relocating point clouds so wherever that cloud imports too is where I start. 

[johnjmbennett]

Hi, 

so the reason they say you should model near theWCS is the accuracy of the modeller, if does not seem to like being too far away when it comes to checking the parts for numbering.  You can find two parts that are the same will get different references, this is down to the decimal places.

so being that the system is metric, I guess using fractions (inches) can cause this to be experdited.

that's what I have always been told over tge reasoning.

as for Coordination, well there are others here using it day in and out, who I expect have a few tricks up their sleeve.

cheers

[Jonathan3891]

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@markhubrich wrote:

I usually apply a transform or use a shared coordinate system. The first job where I experienced the negative effects opened my eyes as to why you want to be close to 0,0,0. The engineer had his model zero many miles away. They kept the survey coordinate location and my model file was instant bloat. Everything does math related to 0,0,0. When all your coordinates of objects have values that show like"6.0640078e+44" then that's too far.

I'd say it really depends on your purpose. In Navis, once you apply transform, it stays. If the models get updated the transform holds. My workflow is to get arch revit model into navis as my base. I then append my very minimal model for the purpose of alignment. That is when I see how far from 0,0,0 I am. If my model requires sharing with 3rd parties for BIM coordination then I will move my model around so BIM coordinator doesn't complain. They don't want to deal with applying transform to every trade. 

If any Navis work is in house then I'll usually place column line intersection A/1 or whatever at 0,0,0 at el.+0'-0". If you then receive  files from other trades then most times you can simply match the transform you gave the arch Revit model to align to your model. 

This is only a small example of scenarios. If you add point cloud data into this mix, well, ask the provider of the data to align to either your coordinates or the Revit model. For me, I have not mastered relocating point clouds so wherever that cloud imports too is where I start. 

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How do you apply a transform or use a shared coordinate system?

[markhubrich]

I'm processing a short screencast. I'll post back when its complete

[markhubrich]

Oh boy ADSK really needs to fix screencast issues here LOL.

https://autode.sk/3adPOzH

https://autode.sk/3arsXRx

[markhubrich]

The 1st one shows glitch in 3DDWF export that always comes in 90 degrees off. This model was already matching in X,Y,Z so it aligned.

The 2nd one I copied that stair to a new file and moved it off purposly to show scenerio. It still had the rotate issue so do that first. If rotation is good this method is similar to moving in ACAD. Then you can see the total transform by right clicking the file and ..

So far 2 methods shown. The 3rd would be close to the 2nd one except we use the x,y,z values shown to shift our model in Advanve Steel. Useful for when your models get shared with a coordinator. This doesn't get us out of the issue of 90 rotation with dwf though. The reason I choose to live with dwf and not NWCOUT or NWDOUT or native dwg is the info dwf contains over the rest.