Coordinating & locating imports in Revit

[kevin_fielding]

Currently, imports into Revit are not aligned with the any national or regional coordinate system but instead are aligned with Longitude and Latitude instead. It would be nice to be able select an appropriate coordinate system such as OSGB National Grid System here in the UK. Coordinates based on Longitude and Latitude aren't of use to us. 

Where a user works to a particular coordinate system it would extremely useful to either

1. specify an insertion point and update the Revit coordinate system e.g. a corner of a building or a location marker in the model

or

2. align the import with the current revit model coordinate system

What is concerning currently is that the addin will overwrite the Revit Shared Coordinate System without prompting the user. 

It may not always be the case that the Revit file will be free of geometry or data. Iterative design development needs to be accommodated. 

Thanks in advance, Kevin

[kronz]

Hi, thanks so much for the feedback! Yes, if there is existing Revit location data it will by overwritten by the GIS coordinate system used to locate the Forma project. 

Just to make sure we understand your desired behavior you'd like

a) to be be warned that the existing location data will be overwritten

b) to have an insertion affordance for geometry (rotate/move incoming 3d elements)
c) to be able to rationalize or choose the incoming or existing coordinate system data to persist

And just to go a little further, if you were able to do these things, can you say a little about what you would expect to happen if you then used the "Updated Propoal" functionality to modify the Forma proposal based on these transformations? 

[kevin_fielding]

Hi Zach, 

I’ve attached what I would expect the process to be.

With regards to updating existing geometry, I would expect the geometry to be updated based on the aligned coordinate systems. You would want to ensure that the imported geometry is correctly geolocated.

Selecting an insertion point based on the attached, would likely in my opinion be the least used option in my opinion (and perhaps the most challenging to implement).  We would normally have shared coordinates established already by this point or would be starting with a blank model and would be happy for the geometry to be inserted center-to-center. 

Happy to clarify anything that isn't clear. 

Thanks, Kevin

[Chris_D_UK]

Just stumbled on this thread while looking for answers to the same problem. In the UK we ONLY use OSGB for everything related to construction - all topo surveys etc are always transposed to OSGB coordinates, and all mapping available to the construction industry is based on OSGB.

Forma needs to support OSGB to have any chance of becoming useful in UK workflows. At the moment we have to import Forma to a separate file to avoid it writing incorrect coordinates to a Revit file, and then link that to the main Revit site model and 'eyeball' it into position - something that's almost impossible to do because the Norths don't appear to align on the two systems!

[Michael_Ruehr]

Same Issue in Australia except we have many local coordinate systems as well some are not even defined in Civil3D

GIS data is generally not accurate enough

It would be nice to be able to Specify Coordinate at Point like in Revit that would give us maximum Flexibility 

Kevins Process Map should work for us  

[kevin_fielding]

Is there any further commentary from Autodesk on this?

Current workaround for Coordinate Systems is

1. Load Forma geometry into Revit. 

2. Get several known location point

3. Use https://epsg.io/  to convert coordinates from UTM Zone 30N to OSGB grid references. 

4. Specify coordinates at point within Revit

5. Check overall true north alignment with secondary points.

7. Identify Coordinate System grid intersection, and mark this using custom coordination marker. 

6. Link file into another model with Project Shared Coordinates (using centre to centre), and manually reposition the linked file. 

As I'm sure you can agree, there are far to many steps required.

[Chris_D_UK]

I discovered yesterday that Forma already knows about all the international coordinate systems, and they're all right there in the app, but only enabled for Imports from IFC, OBJ and DXF. They are not enabled for linking Forma models to Revit. Looks like it shouldn't be too much effort to enable this though!

[kevin_fielding]

Agreed, the import process works a treat. Although it would be great if DWGs were also supported.

There clearly is the ability to translate coordinates systems, the math is beyond me though.  I'd love to see this either at the Forma end of the export I.e. select an export coordinate system, or at the import end I.e. translate the data to this coordinate system in Revit. 

Shouldn't be too difficult 😉

[F.Garcia6Y866]

We are in the same page here, we are converting the Lat and Long and assiging these converted coordinates to Revit Internal and then linking this file into another file...too time consuming

Also have you managed to import any dxf succesfully into forma using the Coordinate System and Coordinates?

[m_kingdon]

I hope that adding more coordinate systems is high on the Forma development team's to-do list.  I am not able to try out Forma on any of my current projects as they are all based on New Zealand coordinate systems.  I don't really want to convert them 😅

[y_naessens]

Hi everyone, 
I can't understand how coordinates are handled from Forma to Revit.
In France here, we have multiple data sources available in Forma including OSM and State OpenData. If Forma can assemble multiple layers from different sources it means Coordinate System is homogenous between OSM and State OpenData (and can be translated from one CS to another). Additionnally, the terrain coming from State OpenData source, has every cs characteristics well described on government website.
When importing in Revit, orientation to geographic North is right but North and East coordinates are completly different from the ones I retrieve on official sources, no matter to which coordinate system I transform them and ratio Xforma/XofficialCoords and Yforma/YofficialCoords has a 10x difference so it appears it's not a unit conversion issue.

Could someone from the Team guide us on how cs are handled at import under the hood ?

[joe_stott_AHR]

Just wanted to keep this thread alive and see if we are anywhere near any updates on this front. As Kevin has highlighted at the moment there is a disjoint between the coordinate systems used in Revit and Forma. Forma appears to have the ability to translate coordinates however this is still to be implemented for the Revit connector. 

Any updates or comments on this would be welcomed as its a pretty key function for us in the UK (and other countries). 

[marthe.brondbo]

Hi all - 

Apologies for this thread falling between the cracks! I have notified the team, and will get back to you as soon as possible! 

Marthe

[samarvir_singh_bhayana]

Hey Everyone,

Thanks for supporting Forma.

Co-ordinate systems are challenging. Even a slight deviation in calculations between two different machines can be catastrophic for projects.

In Forma, We have tried to abstract out this complexity for you. So, that you don't have think about Coordinate systems as you add geospatial data or start drawing.

We are looking into finding ways to extend this abstraction to newer coordinate systems (like British national grid) 

We have made significant progress. We will keep you all posted as we fix this issue.

Best,



 

[Chris_D_UK]

Thanks for the long overdue update Samarvir. If the Forma team are wondering why so few people are yet using Forma for real projects, it's roadblocks like this. Until you support proper integration between Revit and Forma (and coordinate systems are fundamental to this) we just can't use it. This is the basics - not sure why you're adding new features until you've sorted the basics...

[Michael_Ruehr]

Samarvir the "We have tried to abstract out this complexity for you" is at the heart of the issue the Revit Team also tried this and unfortunately the important info is hidden and only available with unnecessary workarounds.

Understand, you want to keep it simple in Forma for quick info and environmental testing but the moment we are in Revit we need to be 110% sure about accuracy. as well in Australia we typically work from Local Flat City Grids none of them are supported in Forma or Civil3d so we need a manual way to adjust locations to millimetre accuracy 

[diana_fox]

Any update on this issue? The whole concept of creating proposals in Forma and sending the proposal into Revit is ultimately flawed if they don't share coordinates and orientation.