Heron traslation/rotation issue with a .shp based on a ED50 UTM Zone 32N reference system

This .shp (2016 version) has a ED50 UTM Zone 32N reference system. I want to convert the cartesian point in decimal degrees latitude and longitude using XYtoDD heron component. I have seen there is a traslation/rotation. How can I correctly use with heron without traslation/rotation in output points?

Replies to This Discussion

Permalink Reply by Brian Washburn on June 1, 2018 at 8:46pm

There seems to be an issue with the way the gdal libraries Heron uses are transforming the UTM reference system in the original shapefile to the WGS84 reference system. This means the shapefile is not being brought into Grasshopper properly. Apparently gdal itself references PROJ.4 to do its transformations and it's possible the version of PROJ.4 gdal 1.11 uses didn't contain the UTM transformations. This seems unlikely to me, so I'm still confused.

The fix for now is to use to a program like QGIS to set the coordinate system of the shapefile to WGS84. Here is a 9mb zip file where this has already been done:

ctc-edifici-WGS84.zip

Let me know if this works,

Brian

Permalink Reply by Francesco on June 2, 2018 at 2:33am

Thank you for your prompt reply.

I'll try the new WGS84 reprojected version on Monday.
Does you have in mind to fix this issue in the next future directly in Heron without to use other external SW?

Permalink Reply by Brian Washburn on June 2, 2018 at 8:01am

Definitely! Thanks for letting me know about this bug.

Permalink Reply by Francesco on June 4, 2018 at 6:40am

Hi Brian,
I have used your WGS84 shapefile.
In Rhino there is a perfect matching between test surface and buildings:

However when I import the csv file containing latitude and longitude (defined with the XYtolat&long Heron component) in Grass GIS, the test surface appears stretched along x axis: