[Therion] LOX: Measure distance from station to surface

[Benedikt Hallinger]

Hi there,
i just wrote a small tool to do the conversion from a therion surface 
mesh into survex format:
https://github.com/hbeni/therionsurface2survex

It would be nice if some C++ programmers can look over the code as this 
is my first c++ endeavour.

The program basically parses the therion source file and generates *fix 
commands out of it together with nosurvey-centerline connecting the 
stations to a mesh.
The resulting .swx file then can be put trough survex' cavern program to 
generate a 3d file of the mesh.
That can be easily combined with a 3d file of the cave generated from 
therion (using the import statements). For ease of use provided a basic 
example for combining in the readme. A sample to parse a mesh is in the 
projects example/ folder, however i also tested it positive with the 
rabbit cave example.

With my dataset the calculation seems to take a little longer.... there 
are 388.800 fixe stations in the surface mesh giving a 31M swx-file in 
total.
I hope this will finish somtime (running already for 25 minutes) but 
maybe i overloaded cavern with this.
Otherwise i probably need to turn down the grid resolution (currently 
10m grid size).



Am 2020-03-26 23:23, schrieb Tarquin Wilton-Jones:
>> However, my aven does not enable me to avtivate it in the view menu, 
>> its
>> disabled (greyed out), i assume because i do not have surface data in
>> the file?
> 
> Sounds like it. It works based on legs that have:
> 
> flags surface
> 1 2 9.8 123 0
> flags not surface
> 
> Or if you have used TerrainTool to export it as a grid, it will have
> added that for you.
> 
> This has been very easy for us in our projects because we either knew
> exactly which line to follow on the surface beforehand, or we surveyed
> the cave first then surveyed over the surface afterwards, staying above
> the passage so we could have a useful measure of the surface above the 
> cave.
> 
> In more complex caves, I rely on TerrainTool to cover the surface.
> Looking forward to being able to use the new more accurate NASADEM so
> that the measurements are actually accurate.