Demystifying the Coordinate system : When is it applied in Civil 3D or Map ?

[cyberflow]

Hi there,

I know how to assign coordinate systems to my drawing, no problem.

But i'm trying to figure out when does Civil 3D work with coordinate ?

Is it when we create points when importing a survey ? When draw alignments ?

Or is it that we always work in a plan grid and then when we want to export there's a transformation applied ?

Thanx all in advance !
It's a pretty hot topic sometimes that is configured by a surveyor on a projet and we stick with that CS (coordinate system) for the life of the project without questionning ourselves.

[cyberflow]

Hi Dave,
"vertical transform between a NAVD88 and a CGVD2013"
I just browsed the tool and didn't find anything either ...
But there's a way of using .byn files from the canadian instances that take care of Datums and convert it into bin
Afterward it's just a question of adding that into the .json file so the tool shows up the new .bin files

I haven't tested this though

"the transform tab is really only for import point"
Ok, I did some reading and the transform tab really affects when we insert something in the drawing after that the objects have been transformed.
-LandXML ?
-Copy/Paste with base point ?
-Binding Xref ?
-Importing text for Cogopoints

I think it's about it for the effect of that tab ?

[cyberflow]

.

[Pointdump]

Frank,
I found the site that stores Geoid files for the entire world. In theory you can download any file lacking in the Vertical Transformation Tool.
>>>International Service for the Geoid<<<
Dave

[cyberflow]

Dave,

Excellent find !

A nice Geoid repository !

Except for Canada it's on demand - Ive did the demand for those files to see if i can have them and integrate them with C3D - Will keep the forum posted on this :

"the transform tab is really only for import point"
I've redone some browsing and searching on this - and can't find no more details other than how to configure that tab.