Coordinate Grid System - Importing From CAD issue

[MKEllis]

Hi,

I may be missing something really obvious here.

We have a site survey drawing - AutoCAD 2014 - which is setup with a Geolocation point with a specific Grid Reference (Ireland OS Grid).

In AutoCAD we can view the map behind the CAD drawing - and the location is correct, the site plan overlays nicely with the map - and the base point has the correct Irish Grid reference.

Can we pull the grid reference for the basepoint in AutoCAD into Revit ? and automatically set that up as the Survey point ?

Many thanks,

Martin

[AJA14 · Accepted solution]

Hi,
To do this you need to understand project base point and survey point. Additionally, you need to understand how to specify coordinates, pull and push coordinates, and so on. Here is a process that works:
1- Go to site view.
2- Import/link the dwg file (link don't import). Ensure that correct import units are used.
3- When you link the file, do that center to center.
4- Pin the dwg file.
5- Go to manage tab and use acquire coordinates to pull the coordinates from the cad file.
6- Now change the orientation property of the site from project north to true north.
7- After you do that, go to manage, position, rotate true north, and rotate the view to an angle which is the angle difference to the horizontal.
This does not change your other views and you can start working on orthogonal views.
8- Now unclip the project base point and move it to the origin location then reclip the project base point.
9- Save your project and click on the save option.
10- Make sure when you export back to dwg you use shared for coordinate system basis in the export dialogue box.

Another way is to simply specify coordinates at a point using known coordinates, then rotating project north to get your orthogonal views.

Others might have different approaches so good luck.

regards,

[MKEllis]

Many thanks for that concise summary Ali - will probably print that out and pin it to my wall.

For some reason when I was trying to acquire coords from the linked CAD file - it wasn't working.

I started from scratch, and repeated the process as you set out there, and it worked - Thank you.

Not sure what step I was missing or getting wrong - but I must have skipped something.

As an aside - why is it that Revit doesn't appear to read the Latitide / Longtitude from the CAD geo-positional data to identify the location ? Even once everything is shared across the coordinates and the CAD file has specific Lat/Long values, in Revit under Location (Internet Mapping Service) it still shows the default location and weather station (in this case London). Not a biggie I guess, but still a quirk.

Thanks again,

Martin

[AJA14]

Hi,

Glad it worked for you.

WIth regards to the lat/long, these are related to solar studies and not shared coordinates.

Regards,

[MKEllis]

Thanks Ali, I realise that the location is only used for environmental data (well solar + closest weather station data) but it would be nice if this was somehow linked to real-world Long/Lat if available - just to save that one step. As I say, no biggie really.

Thanks again,

Martin