Local Coordinate System (arbitrary units)

RE: Local Coordinate System (arbitrary units)

Brian Fitzpatrick — Fri, 29 Oct 2021 20:56:01 GMT

excellent

RE: Local Coordinate System (arbitrary units)

Oto — Fri, 29 Oct 2021 19:59:56 GMT

Defect Report 736903

RE: Local Coordinate System (arbitrary units)

Oto — Fri, 29 Oct 2021 16:37:35 GMT

It was just an observation when selecting vertical system override it creates new custom coordinate system definition like EPGSxxxx+EPSGzzzz so seems logical that this approach is also some undocumented way how units are defined. CC uses GDAL/OGR library for coordinate transformations so it helps also.

But seems they forgot to add this also to standard install not only for measurement as there were such change in U8 and CC Console U2. Will try to report it.:

- Measurements in US survey feet (new unit system settings)

RE: Local Coordinate System (arbitrary units)

Brian Fitzpatrick — Fri, 29 Oct 2021 16:16:16 GMT

Oh, just realized what you meant, yes I just re-AT'd it with "Local:unit=Survey Feet" for a new coordinate system and that worked, thanks Oto, I've never seen that workflow in any Bentley learning manual/training. Where do you learn these things?

RE: Local Coordinate System (arbitrary units)

Oto — Fri, 29 Oct 2021 11:57:52 GMT

Why did you not try my approach and click More, then SRS database and add custom SRS - "Local:unit=US Survey Feet".

But your workaround also works just it doesn't set units for production it only changes default unit for measurements in online viewer.

RE: Local Coordinate System (arbitrary units)

Brian Fitzpatrick — Thu, 28 Oct 2021 20:29:13 GMT

It does not work for inputting GCP's because ContextCapture does not allow you to input US Feet when you have local coordinate

system. Only "meters" and "arbitrary units", so I converted my US Feet coordinates to meters, and entered them as meters. At least now it was to scale only wrong units.

I process reconstruction on the cloud processor, before I submitted production, I changed unit system under settings to US Survey Feet, and it worked perfect.

RE: Local Coordinate System (arbitrary units)

Oto — Thu, 28 Oct 2021 20:11:54 GMT

How did you manage to change units at reconstruction and why it didn't work for GCPs?

RE: Local Coordinate System (arbitrary units)

Brian Fitzpatrick — Thu, 28 Oct 2021 17:27:35 GMT

Yes, that worked, so the workflow:

AT: convert US FEET GCP's to meters (multiply by 0.3048) than add GCP's to model, than perform AT

RECONSTRUCTION: Make sure chnage units to US Feet than resonstruct

RE: Local Coordinate System (arbitrary units)

Oto — Thu, 28 Oct 2021 14:19:32 GMT

Shouldn't be a problem at all.

Try to create a new local coordinate system with value - "Local:unit=Survey Feet"

. Use metric one as template

RE: Local Coordinate System (arbitrary units)

Brian Fitzpatrick — Thu, 28 Oct 2021 14:07:54 GMT

thnaks Oto, the problem is the origin (0,0,0) is too far away from the model, so ContectCapture does not have the ability to put custom coordinate system in US Feet?

RE: Local Coordinate System (arbitrary units)

Oto — Mon, 25 Oct 2021 09:05:26 GMT

To define your own local system then use constraints by setting origin and axis direction. Otherwise you would need to define custom coordinate system.

Arbitrary is used when there is no measurements as proportions in model are correct but scale is not.