Autodesk / Autodesk/revit-ifc

Revit doubles up georeferencing data

Open
#177 1 comment 0 reactions 0 assignees View on GitHub
coordinate system Triage
Dominant language
C#
Stars
637
Forks
225
PR merge metrics
No merged PRs in 30d

Description

World coordinates are currently exported into the IfcSite object. If the user instead would like to specify eastings, northings, rotation, and EPSG data as part of the georeferencing entities (or psets for 2x3), then there is no way to "remove" the equivalent data from the IfcSite, as well as the elevation data for IfcBuildingStorey.

If you read https://wiki.osarch.org/index.php?title=Revit_geolocation - you will see just how convoluted the vertical georeferencing procedure is in Revit. At the very least, the IFC exporter should know when the native IFC georeferencing entities are being set, and adjust the rest of the export's coordinate appropriately.

Also, "leave the project base point at 0,0,0 and don't rotate" is not a solution, as that breaks the spot elevation feature in Revit, and breaks the rotated scope box workflow used for true north that so many firms rely on.

Contributor guide

Open the contributing guide

Research direction

No source files, tests, or entry points are identified in the issue. Start by reviewing the Revit geolocation guidance linked in the report and locating the exporter code that writes IfcSite, IfcBuildingStorey elevation, and native georeferencing entities. Done means native georeferencing no longer duplicates or conflicts with exported project and elevation coordinates.

Written by the indexing model from the issue text.

Assessment

Tech stack
csharp
Domain
backend
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.