Exporting shapes in a different coordinate system

[Thibaud Capra]

Hello,
I'm currently willing to be exporting shapes in a different coordinate system than my project's.
My photos are in WGS 84 so are my dense clouds etc. but I can export them in Lambert 93 / CC 48 without any issue. The only exception is the shapefiles I have, is there any way to do it?

Some coworker suggested me to use ogr2ogr from GDAL but I don't really understand how.

Any help is appreciated.

[Alexey Pasumansky]

Hello Thibaud,

Do you have a EPSG code for this system?

[Thibaud Capra]

Hello Alexey,

Sure: Lambert 93 / CC48 code is EPSG::3948

[Alexey Pasumansky]

Hello Thibaud,

Then you probably should use the following:

Code: [Select]

crs = PhotoScan.CoordinateSystem("EPSG::3948")
chunk.exportShapes(path, projection = crs)Doesn't it work correctly on your projects?

[Thibaud Capra]

Hello Alexey,

On my projects, I choose the crs during the exports individually, ie. the orthomosaics are exported as follows:

Code: [Select]

        # Export Orthophoto
        path_ortho = path_export_chk + chunk.label + "_Ortho" + ".jpg"
        chunk.exportOrthomosaic(path_ortho, format = "jpg",
        raster_transform = PhotoScan.RasterTransformNone,
        projection = PhotoScan.CoordinateSystem("EPSG::3948"),
        write_world = True)
I tried using your code (PhotoScan version 1.2.6) and it's not working, projection = crs being and incompatible keyword. Here's my current code, more or less working. More less than more though, as I get the error message "Can't export shapes." when running it.

Any idea why?

Code: [Select]

import os
import PhotoScan

print(""">>> Initialisation du script IV <<<""")

doc = PhotoScan.app.document

path_export = PhotoScan.app.getExistingDirectory("""Spécifiez le dossier
 contenant les exports en fin de traitement""")
path_export += "\\"

print(""">>> Génération des fichiers de sortie <<<""")

for chunk in doc.chunks:
        # Create a new folder
        path_export_chk = path_export + "_SHP"
        if not os.path.exists(path_export_chk):
            os.makedirs(path_export_chk)
        path_export_chk += "\\"

        path_export_shp = path_export_chk + chunk.label
        if not os.path.exists(path_export_shp):
            os.makedirs(path_export_shp)
        path_export_shp += "\\"

        crs = PhotoScan.CoordinateSystem("EPSG::3948")
        chunk.exportShapes(path_export_shp)
       
        PhotoScan.app.update()

print(""">>> Fichiers exportés ! <<<""")

doc.save()

PhotoScan.app.update()
print(""">>> Script Partie IV terminé <<<""")

[Thibaud Capra]

Bumping topic, is it because my shapes are in a different layer that is not the default one?

[Alexey Pasumansky]

Hello Thibaud,

In the version 1.2.6 it wasn't possible to specify the export coordinate system for shapes, so it has been exported in actual shapes.crs system.

In your code line crs = PhotoScan.CoordinateSystem("EPSG::3948") is meaningless, as crs variable is not utilized after that. But export problem seems to be related to the incorrect path specified. The last modification of the export path variable is path_export_shp += "\\" - it means that the path is not ending with the file extension, for example, ".shp", but is the path to the folder.

[Thibaud Capra]

Hello Alexey,

I thought that since the exportShapes command created multiple files with different types, it did not require any extension for the path.

Thanks for your help, I'll run it ASAP and see if the fix works.

[Alexey Pasumansky]

Hello Thibaud,

There could be additional files if you are saving in .shp format, but you still need to specify the full export path including filename to that .shp file.

[Thibaud Capra]

Hello Alexey,

Thanks for the explicit answer!

To get my shapes in the coordinate system I want, could there be a way to get them by transforming the project's coordinate system from WGS84 to L93/CC48 before exporting the files? If so, how can I do it in 1.2.6 ?

[Alexey Pasumansky]

Hello Thibauld,

Switching the coordinate system of the chunk wouldn't help, because the shape coordinate system is stored separately. I think the only way inside PhotoScan would be transforming the coordinates of every shape in the project from the source coordinate system to the new one.

[Thibaud Capra]

Hello Alexey,

How would you do this in 1.2.6? I understood you can't change it during exports?

[Alexey Pasumansky]

Hello Thibaud,

I would modify the coordinates of the shape vertices recalculating the coordinates from WGS84 to L93/CC48, then (when all the modifications are performed) re initialize shapes.crs to the new coordinate system and then export shapes.

For testing you can use a single simple shape.

[Thibaud Capra]

Hello Alexey,

I'm kind of bumping this topic because I haven't figured out how to do it.

A simple piece of code exporting the shape from whatever his coordinate system is (here I believe it's WGS84) into L93/CC48 would do... Could you help me once again ?

[Thibaud Capra]

I guess I should use something the like of:

Code: [Select]

PhotoScan.Shapes.crs.transform(EPSG::4326, EPSG::3948)
PhotoScan.Shapes.crs.update
Then I'd export my shapes, right?