Hi @keesvanprooijen,

The standard Mapinfo files have a limited coordinate precision, which can cause coordinate rounding for large coordinate values. To work around this, Mapinfo internally offsets coordinates to make the actual coordinate values smaller. These offsets are based on the coordinate system of the data. To prevent the rounding, please ensure that the output coordinate system is being set properly.

From the coordinates you have supplied, the coordinate system is likely a type of Tranverse Mercator (UTM, Gauss-Kruger, etc.). If there is no coordinate system read from the CityGML data, the default coordinate system in the Mapinfo file will be local (Non-Earth Meter), which is not appropriate for the coordinate values you have. You can set the correct coordinate system in your workspace, using the coordinate system parameter on the CityGML reader.

If the coordinate system is correct, and rounding still occurs, try setting the Bounds parameters for the Mapinfo writer to a fairly tight bounding box around your data. This further refines the offsets Mapinfo uses, and ensures the greatest precision in your output file.

If you have newer versions of FME and Mapinfo, you may also wish try the new Mapinfo Extended Tab format, which I believe has an improved coordinate precision. As well, the Mapinfo MIF/MID exchange format (which is text instead of binary) has no limitations on the coordinate precision.

Thanks. The coordinate system of the input files is EPSG:28992.