[Therion] LOX: Measure distance from station to surface

[Tarquin Wilton-Jones]

> does anybody know how i can measure the distance from a given station to
> the surface, when i have a surface model loaded?

I have always done this with Survex's Aven. Export 3D, open in Aven,
enable surface legs, click the station, hold mouse over the surface
legs. (I do this with either surface survey stations, or surface grid
that I prepared with TerrainTool.)

Aside:
If you use Survex rather than Therion to export this, the ends of the
splays become clickable points in Aven, so you can measure from your
highest splay. If you use a 3D exported by Therion, then you cannot
click on the splays. Therion does not add the control point at the end
of each splay (I have filed a bug for that).