Hey All,
Just wanted to ask if folks out there can define the 3 types of units of measure that are displayed in Design File Settings and GCS. Please define what the Linear Units are, the Advanced Settings Resolution units are, and what the GCS units are. Also, what is their relationship with one another?
Linear Units: Are these what you are reading out when measuring? So when I have XY coordinates displayed, they're supposed to be displaying values in whatever unit of measure is listed for Linear?
Advanced Settings Resolution Units: I understand what resolution is, but where does the unit of measure come into play, and more importantly, what is the relationship between this and the Linear Units unit of measure? I assume these and the linear units should match, although I have heard of circumstances where they differ.
GCS: Establishing your GCS is to the effect that you're saying what projection/coordinate system your data is in
Hi Neil,
well, you opened quite complex question ;-)
Neil Usefara said: the 3 types of units of measure
They are not "units of measure" to be precise. In fact, it's about mixing different concepts and to compare apples and oranges.
Neil Usefara said:that are displayed in Design File Settings and GCS.
It would be nice to follow, as Jon asked, the best practices, and to specify used product, its version, and also to provide more precise information what setting do you mean. To share e.g. a picture of dialog or a link to documentation, where the setting is described, makes the discussion simpler and more efficient.
Neil Usefara said:Advanced Settings Resolution Units
General recommendation is "do not touch them", because when you will change them, you will (A) probably corrupt existing model (because its size will change) and (B) there are some consequences when DGN V8 is exported e.g to V7.
These settings describes how values (coordinates) are stored internally in DGN V8 and also provide some basic information what they mean. Default values fit (I guess) 99,9% of scenarios. To change the setting is possible, but it's recommended to know very well how DGN V8 format is designed and what consequences are.
Neil Usefara said:Linear Units
They are units you choose to work with. They do not tell anything more than when a value is used to express a coordinate, what it means for the user (which, typically, is equal what it means in real world).
Working units have no relation to how coordinates are stored, because they are converted into UOR (units of resolution) at background. In other words, when one model uses meters and another millimeters, internal value can be the same.
Neil Usefara said:GCS
GCS system is built on top of working units, and as you wrote, it adds extra information about used geographic coordinate system.
With regards,
Jan
Bentley Accredited Developer: iTwin Platform - AssociateLabyrinth Technology | dev.notes() | cad.point
Jan Šlegr said:well, you opened quite complex question ;-)
And something you really need to understand completely if you want to get very far with Microstation.
Connect r17 10.17.2.61 self-employed-Unpaid Beta tester for Bentley