Agisoft Metashape Professional allows to perform the coordinate transformation between two geographic/projected systems in two cases:
- both systems are based on the same datum;
- both systems have ToWGS84 parameters specified in the coordinate system definition (this includes the systems that are already based on WGS84).
By default, the system definition is taken from EPSG registry, but if the default transformation parameters are not accurate or even missing, it is possible to input them manually or choose from the list of available transformations.
To define ToWGS84 transformation parameters Datum Transformation Settings dialog should be accessed by pressing the corresponding Datum Transformation Settings button to the right of the coordinate system selection field in the Reference pane settings dialog or Convert Reference dialog:
Note that via Reference pane settings dialog it is possible to set up the transformation parameters for the currently selected systems (assigned to cameras, markers, or complete chunk), whereas the Convert Reference dialog allows to define the transformation parameters for the target system used in the conversion.
In the Datum Transformation Settings dialog, it is possible to select the set of the parameters according to the transformation from EPSG registry (via To WGS84 field) or use Custom option and input the corresponding parameters manually.
Alternative way of the transformation parameters definition is to define the corresponding coordinate system by loading the PRJ file which contains TOWGS84 sub-section in DATUM section, like in the example below. Keep in mind that in case of custom TOWGS84 parameters used it is suggested to remove the AUTHORITY sub-section related to DATUM section:
PROJCS["NTF (Paris) / Lambert Centre France",
DATUM["Nouvelle Triangulation Francaise (Paris)",
SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627,