[Therion] LOX: Measure distance from station to surface

[Benedikt Hallinger]

cavern had eaten itself, but after pushing ctrl-c in the shell running 
therion, the 3d  file was written successfully and the output was nice.

I enhanced the therion wiki a little with a link to the tool.

Sorry, i have no clue how to cross compile this for windows.


Am 2020-03-27 23:51, schrieb 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.