i tried to open an IFC-file (yes, it is a textfile] in gdl object. The file contained terrain inEUREF-FIN / ETRS-GK26FIN coordinate system1st two rows:id xcoord ycoord zcoord8025672 477183839.999 7212389619.967 21070 -the coordinates are millimeters, not meters.My object cou...

This might help.https://community.graphisoft.com/t5/GDL/Dynamic-Polyline-base-code-object-VERSION-2/m-p/249973#M4455

Hi John. Here is something to start with. New verts are created by moving the hotspot in the circle.

I have wondered that, too. Try to draw 3d elements in the right place. If You later move them they possibly remember their original coordinates. That is my impression.

Maybe curves are too detailed. You can reduce any polyline in QGIS and export to dxf.. It´s free and it is very useful for landscape architects.