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1

Bug Reports / Bad region when using resetRegion()

« on: September 19, 2019, 01:03:20 PM »

Hello,

if I understand correctly, the region should be set automatically after alignment or when we use chunk.resetRegion()

I do not know how it works but sometimes the region is very smaller than the results of the spare cloud.

In the screenshot, we can see that a big part of the sparse cloud is outside the region, even if i use chunk.resetRegion(). And then, my automatic script will build a dense cloud without this part (+ DEM + Ortho). The bad region calculation will give me partial outputs (bad for me)

What is the criteria used to keep or not some points? I still want to keep out outlier points, but those points are not outlier. How can i keep them automatically?

2

Bug Reports / Different WKT content between CRS definition and output files

« on: July 25, 2019, 12:45:38 PM »

Hello,

I runned a process with this CRS: EPSG:27562.
The WKT of this CRS is that:

Code: [Select]

PROJCS["NTF (Paris) / Lambert Centre France",
    GEOGCS["NTF (Paris)",
        DATUM["Nouvelle_Triangulation_Francaise_Paris",
            SPHEROID["Clarke 1880 (IGN)",6378249.2,293.4660212936265,
                AUTHORITY["EPSG","7011"]],
            TOWGS84[-168,-60,320,0,0,0,0],
            AUTHORITY["EPSG","6807"]],
        PRIMEM["Paris",2.33722917,
            AUTHORITY["EPSG","8903"]],
        UNIT["grad",0.01570796326794897,
            AUTHORITY["EPSG","9105"]],
        AUTHORITY["EPSG","4807"]],
    PROJECTION["Lambert_Conformal_Conic_1SP"],
    PARAMETER["latitude_of_origin",52],
    PARAMETER["central_meridian",0],
    PARAMETER["scale_factor",0.99987742],
    PARAMETER["false_easting",600000],
    PARAMETER["false_northing",200000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["X",EAST],
    AXIS["Y",NORTH],
    AUTHORITY["EPSG","27562"]]

When i print the wkt from python console, i got the same content, it's ok:

Code: [Select]

>>> chunk.crs.wkt
'PROJCS["NTF (Paris) / Lambert Centre France",GEOGCS["NTF (Paris)",DATUM["Nouvelle Triangulation Francaise (Paris)",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627,AUTHORITY["EPSG","7011"]],TOWGS84[-168,-60,320,0,0,0,0],AUTHORITY["EPSG","6807"]],PRIMEM["Paris",2.33722917,AUTHORITY["EPSG","8903"]],UNIT["grad",0.01570796326794895,AUTHORITY["EPSG","9105"]],AUTHORITY["EPSG","4807"]],PROJECTION["Lambert_Conformal_Conic_1SP",AUTHORITY["EPSG","9801"]],PARAMETER["latitude_of_origin",52],PARAMETER["central_meridian",0],PARAMETER["scale_factor",0.99987742],PARAMETER["false_easting",600000],PARAMETER["false_northing",200000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","27562"]]'

As you can see, the PRIMEM value of GEOGCS section is:

Code: [Select]

PRIMEM["Paris",2.33722917,AUTHORITY["EPSG","8903"]]


But, after doing any export (export DEM, export Ortho) as GeoTiff, the WKT content in the header of the tif file is different :

Code: [Select]

PROJCS["NTF (Paris) / Lambert Centre France",
    GEOGCS["NTF (Paris)",
        DATUM["Nouvelle_Triangulation_Francaise_Paris",
            SPHEROID["Clarke 1880 (IGN)",6378249.2,293.4660212936269,
                AUTHORITY["EPSG","7011"]],
            TOWGS84[-168,-60,320,0,0,0,0],
            AUTHORITY["EPSG","6807"]],
        PRIMEM["Paris",2.5969213],
        UNIT["grad",0.01570796326794897],
        AUTHORITY["EPSG","4807"]],
    PROJECTION["Lambert_Conformal_Conic_1SP"],
    PARAMETER["latitude_of_origin",52],
    PARAMETER["central_meridian",0],
    PARAMETER["scale_factor",0.99987742],
    PARAMETER["false_easting",600000],
    PARAMETER["false_northing",200000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AUTHORITY["EPSG","27562"]]

As you can see, the PRIMEM value of GEOGCS section is:

Code: [Select]

PRIMEM["Paris",2.5969213]

Because of the difference of this value (2.33722917 VS 2.5969213) i have a shift in longitude in my exports. (note that is the same thing for pointcloud LAS export).

Why Metashape does not write the same WKT content as the used chunk CRS? Is there something to do in Metashape to change that?

Thank you.