I am trying to input GCP's into my model of a power plant that is on its own coordinate system, my surveyor gives me units coordinates that are is (US FEET). ContextCapture does not offer an option for local coordinate system in these units, only offers "meters" and "arbitrary". Does anyone know the workflow to perform this in US FEET? And why would anybody use a meaningless arbitrary unit?
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.
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?
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
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
How did you manage to change units at reconstruction and why it didn't work for GCPs?
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.
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.
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?
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)