Export shapes with same coordinate system as custom-view orthomosaic

[PeterBetlem]

Hi!

I have been struggling with an otherwise very simple task: exporting annotations and shapes in the same coordinate system as used for the orthomosaic.
The export works as expected when the orthomosaic is top-view and has a "normal" crs. However, I have not been able to export "projected" shapes from a custom-view or side-view orthomosaic.

In this case, my custom-view orthomosaic uses epsg:4978, but with negative X and huge Y coordinates, e.g.:
WGS 84 (EPSG::4978) -1931.398 X 6357705.971 Y

Obviously, there is a working transform - as the shapes are successfully printed on this side-view. Would anyone be able to help me out and point me to the obvious; any idea on how to access this transform and use it for the export of the shapes in the same coordinate system as the orthomosaic?

Any help is greatly appreciated!

[Paulo]

Hello Peter,

to get the shapes  coordinates in the  exported custom view ortho CS, you need to apply the orthomosaic projection matrix to each shape geocentric coordinates (EPSG 4978).

Given a selected shape s, then the  coordinates of each vertex v in the orthomosaic custom view (side) CS are O.mulp(chunk.shapes.crs.unproject(S.inv().mulp(v))) where:

Code: [Select]

chunk = Metashape.app.document.chunk
O = chunk.orthomosaic.projection.matrix
S = chunk.shapes.projection.matrix
for s in [s for s in chunk.shapes if s.selected]:
    if s.geometry.type == ps.Geometry.PolygonType:
        for v in s.geometry.coordinates[0]:
            print(s.label,O.mulp(chunk.shapes.crs.unproject(S.inv().mulp(v))))
    else:
        for v in s.geometry.coordinates:
            print(s.label,O.mulp(chunk.shapes.crs.unproject(S.inv().mulp(v)))) see attachment

A script could always be developped to export the shapes in the custom ortho projection in csv format for example...