Thanks for the info. Seems that the data is not exported to the .3d format indeed. If I have the time I will try to find the place in the Therion sources where that export happens.

On Thu, Mar 24, 2016 at 3:50 PM, Olly Betts <olly@survex.com> wrote:

It should be fairly easy to update - just call img_open_write_cs()
instead of img_open_write() and pass in the PROJ4 projection string for
the output coordinate system as an extra parameter.

I didn't understand that part. What would be easy to update?

Those two functions are part of the Survex source (img.c) from what I see.

Vlad