Exporting to Survex for passage tubes viewing

[Olly Betts]

On Mon, Feb 14, 2022 at 10:39:47AM -0500, Luc Le Blanc wrote:
> Thanks for the answers. I adapted my code. Ghost lines are now gone
> from my cave sample, although I now get blanks in the tubes, but this
> seems to be due to side passages forking from the main gallery.

Sounds like you aren't putting a tube cross-section at the junction
when you start a new tube for a side passage.

Ideally you want a cross section at the junction station *in the
direction of the side passage*.

Sadly in practice the surveyors may not have measured one.  If adding
passage data by hand I'd probably either take up and down from another
cross-section at the junction point and guess suitable left and right
from the sketch, or make up LRUD based on the first station in the
side passage proper, but if you're generating it's harder to do
something reliably sensible.

> I export station names as input by the user, but I notice Aven renders
> them all in lowercase. I can understand case-insensitivity, but why
> force lowercase?

For consistency mostly.  You can leave case as-is if you want (see *case
docs) but then you'll need to spell names with a consistent case as the
comparisons are exact.  That's not something I'd recommend in a filter
which exports Survex data; it's really a choice that needs to be made
for a whole dataset as it's fiddly to link Survex data with the default
case folding with data that expects case to be preserved.

> Two simple questions about the SVX format:
> 
> - can I append LRUDs after each survey shot without having to declare
> a passage?

Yes (using `ignore` or `ignoreall` readings) but they'll be completely
ignored by cavern rather than displayed as 3D passages in aven.

> - can backsight compass and clino now have a calibration?

I'm confused by the word "now" in your question.

I'm pretty sure they've always had separate calibrations to foresight
instruments.  There's been a testcase for it in the testsuite since
2014-11-11, so definitely since Survex 1.2.17.

> On minor addition I'd welcome in Aven in a File/Close menu item to
> close the current cave without having to exit the program. This would
> be convenient to reload an SVX after changes to my export routine.

If you load a new file it replaces the current one, so an explicit close
operation would just add an unnecessary extra step.

There's an even easier way to reload/reprocess the current file though:
Alt+F then 1 (since it'll be the most recent entry in the recent files
list).

Cheers,
    Olly