Exported Ortho 50m away from where it should be!

Development Asset Creation Photogrammetry
1

Hi - I’ve been having trouble with my exported orthos not appearing where they should - they keep consistently locating themselves 50m southwest of where they should be. This is happening with multiple models. I’ve georeferenced everything correctly, as when I export an OBJ and import it into ArcGIS it is correct. Also when I drop the ortho into the map view of Reality Capture it is correct. The centre coordinate listed in the ortho projection settings in Reality Capture is also correct, and I have been careful to make sure my project environment settings are all set correctly.

I’m working in British National Grid (EPSG:27700) and I’ve noticed that on export the OBJ has the correct coordinate system listed in ArcGIS, but when interrogating the ortho’s spatial referencing system it doesn’t seem to appear in the same way (listed as Transverse Mercator with the correct meridians etc, but not keeping the epsg identifier and other small differences). The tfw definitely has the wrong coordinates in the text file

I’ve tried export using every conceivable combination of type (global, projected, image) and it makes no difference. If anyone has any great tips on how to fix this, other than georeferencing externally, that would be much appreciated!

Cheers.

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Just following up on this with some progress in case anyone else comes up against this problem.

I worked out that when I brought the tiff into ArcGIS the coordinate system had not been been properly applied to the layer when exported from Reality Capture. It was ‘unnamed’ and as a result it had used the wrong spheroid (WGS instead of Airy 1830), which would be sufficient to send the layer 50m in the wrong direction. If I manually defined the projection of the ortho tiff in ArcGIS as British National Grid then it plotted correctly.

The big question here then, is why the exported ortho doesn’t have the coordinate system properly applied when it works fine for other kinds of exports (obj for example).

It’s fixed for now using this workaround, but it’s an extra step I will have to take with all my models in this system.

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Hello @HenGoodchild
During the ortho creation only WGS84 CS is written directly to the file. The other systems need to be defined in the viewer to show the ortho properly.