I think that by XYZ the OP (Jono) has always meant CSV with X, Y, Z columns.
I did mean a xyz file, and Manifold failed to import, got to 50% and stopped (it could be the file)? Manifold 9 failed completely in the import, would not even start to process, and then crashes.
Because the xyz failed I converted to a csv, with an xyz. For some reason the newest version of 8 would not turn anything into a surface, stalled each time, even after I had chopped into smaller files. So I suspect there is something at fault in the M8 version or at least in my install. This used to be such a reliable feature.
OK so that's what I needed to know. I can't use M9 to create contours unless I already have the surface created (which would be easy in M8 if it wasn't crashing/ stalling...let it run for 12 hrs only 1%). Would be a great thing to add to help - go to M8 if you want contours from data other than a raster.
Look forward to seeing Manifold 9 become the trusted software I have known of the past, its showing promise.
Can anyone explain what the triangulation is actually for in M9? Is it just experimental?