I am using this video tutorial to create ground contours for a noise model in iNoise.
https://www.youtube.com/watch?v=JxCxBREEqG0
See tutorial 8 https://dgmrsoftware.com/products/inoise/gallery/
When I import the dxf file it has no height data. Not sure where I'm going wrong as all the layers have height data when checked in QGIS.
It seems I loose it when exporting as a dxf.
This question may indicate that dxf has no height values but is drawn to height. Not sure.