[Therion] Breaking a loop at a specific station on extended elevation

[Bruce Mutton]

Hi Wookey, Tarquin,
I agree that extended elevations are too unpredictable, hard to use, and
that there needs to be a simpler way.  Not sure if it is that there are
bugs, that instructions and understanding is inadequate, or if there is
required functionality that is missing.

Because extend ignore is usually associated with a survey network junction
(nearby or not so nearby), I have a gut feeling that specifying a leg
(perhaps with sensitivity to direction) will generally give more refined
control.  To use extend ignore to break at a particular station, using just
a single station (if I have it right), you need to specify the station one
leg beyond the desired break (a bit like 'flip' in PocketTopo).  Generally,
I find this approach to result in cognitive overload!  If you want the break
at a junction, you would often need to specify which leg anyway, depending
on whether Therion's auto extended generation was incoming to or outgoing
from the junction.

Extend ignore directly controls branching, and only indirectly controls the
break-point in the centreline.  So perhaps the issue is missing
functionality.  Do we need direct user control over the break stations?  It
would be nice.

Extend ignore also feels like a very indirect way of specifying network
generation.  As someone mentioned a long time back, it would be easier to
specify 'extend force <leg>' rather than 'extend ignore <leg>'.   ie
'Specify take this leg, rather than specifying take a different leg'.
Especially where there are more than three branches emanating from a single
station.

While I would welcome Therion improvement in this space, I am a little
concerned about all of my existing extended elevations that might be broken
by changes in behaviour.  I'm sure this eventuality can be accommodated by
clever coders however.
:)
Bruce

-----Original Message-----
From: Therion <therion-bounces at speleo.sk> On Behalf Of Wookey
Sent: Tuesday, 12 November 2019 11:18
To: therion at speleo.sk
Subject: Re: [Therion] Breaking a loop at a specific station on extended
elevation

On 2019-11-12 07:20 +1300, Bruce Mutton wrote:

> I don't have a problem with the characteristic you mention in point 2.  I
think it is just semantics associated with the word 'ignore', and sequential
process.  If you think 'break' then is it all OK?

We think it should be possible to specify 'break/ignore' at a point, rather
than a point+direction (i.e. a leg/pair of points)
We want the computer to worry about the 'direction' aspect, and feel we
shouldn't have to. It seems like this should be possible.

Wookey
--
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