linking to GIS coordinates

[Anonymous]

Hello,

I've been asked by an municipality to link a cad drawing to TX83-CF coordinate system so that they can place my drawing in their design software. Can someone give me some clues to how I can link a drawing to a specific coordinate system in Archicad?

I can locate the project in my City, but that is not what they are asking for. I believe you can link an Autocad drawing to a specific GIS system as noted above.

Best,

Travis G. Young, AIA

[Miha_M]

Try using the Survey Point built-in library element. You do have some Surveying data?
This Knowledgebase Page explains how - https://helpcenter.graphisoft.com/knowledgebase/64176/

I can't help you with TX83-CF, as I live in a metric world. But as long as you have a reference point from the Surveying data, the only thing you need to do is to place one Survey Point marker with according location and orientation data. Probably your project working units should match the TX83-CF standard.
This works with .ifc model data export; I don't know if it works with other file types.

[Erwin Edel]

If you have a site drawing that conforms to the coordinate system, you can import that 2D information to a worksheet in your file. You probably need to account for it having a different drawing unit, since it is supposed to cover a lot of terrain and the coordinates values would get very large.

No idea what the conversion works out for with imperial system. I think the SPCS 83 uses meters, so 1 foot = 0.3048 m ??

Over here in the Netherlands our coordinate system uses meters and you typically draw in mm in ArchiCAD. This means I just need to copy my ArchiCAD siteplan and scale it down 1:1000 and move it to the correct position on my worksheet with the imported site plan. Export that as DWG and the government is happy.

IFC exports are more typically used for contractors on site, rather than the government.

[Christophe Fortineau]

Autodesk and Archicad was born nearly at the same time and they use different way of georeferencement. I don't know about your solution but if there is a solution I'm interested about it (today I don't think so). 😕

In France request formatting from a proprietary file (dwg, rvt, pln, psd, etc.) is illegal for a public body.

[stefan]

Can you ask the city to provide you with a DWG file you can use as reference with origin properly set up?

[Christophe Fortineau]

stefan wrote:
Can you ask the city to provide you with a DWG file you can use as reference with origin properly set up?

The risk with this method is that the project can be placed very very far from the absolute origin, which irreparably causes errors in displays in three dimensions among others.

[GOBA]

I thought the survey point would be the solution to the problems caused by having the model very far from the 0,0.

I am also interested in knowing how to georeference, in ArchiCAD.

[a2o-architecten]

Any solutions yet on this topic? Would like to know a solution/workflow for georeferencing a 2D plan in Archicad and exporting it to DWG. Maybe there are add-ons available to do this?

[Erwin Edel]

Step 1: import a 2D site drawing in Archicad on a worksheet (that conforms to the needed coordinate system / norm)

Step 2: add your building contours to this worksheet

Step 3:  save as DWG

This works fine for us.

There are many coordinate systems in use worldwide, so there really isn't one fixed solution I would guess.

[a2o-architecten]

@Erwin Edel , thanks for your feedback.

Just also found this workflow using the new Native Survey Point, we are testing it now. Works only in AC25.  Apparently its useful for IFC as well DWG exports. Don't know yet if it also works for lay-outs that uses drawings from worksheets.