Tarquin

I think Martin is right.  And your example illustrates it well.

Your drawing shows two scraps, the red scrap should have a line at the pit of 
-outline out.  The green scrap should have a line at the pit of -outline out.  
Outline in or outline none has no place in this example.  Whether these scrap 
end lines (margin between red and green) are invisible walls or pit lines is a 
different consideration, and could be handled a number of ways.  The line pit 
itself could be in either scrap (or both, but preferably not).

 

Maybe it is like this:

*       Line orientation (yellow tick) primarily controls orientation of line 
ornamentation.  By convention it doubles as a way to determine the interior of 
an object (rock, passage) or the free-space side of the line.  Usually these 
two criteria correlate perfectly (think of line wall:sand or line pit), but 
sometimes these criteria are in conflict, and the draughtsperson needs to get 
creative!
*       Line outline attribute is primarily for definition of the interior of a 
scrap.  This differs subtly from thinking of it as the interior of a passage.  
Imagine a passage and oxbow.  If they are all drawn as one scrap, the interior 
wall must be -outline in.  If they are drawn as two or more scraps, all the 
walls must be -outline out.  In some cases Therion can already compensate for 
user error, and maybe in future it might be appropriate to automate it.
*       These are two separate considerations that are (and should continue to 
be) handled independently (whether by the user manually or automatically by the 
software).

 

>1. Whether "-outline out" is actually the correct thing to use when the pit 
>line points outwards rather than inwards.

As per the points above.  They are two mostly independent considerations.

 

>2. Why it even matters which way we draw a *wall*, if "outline out"

As you have picked, the pdf engine can solve the problem of what is the inside 
of a passage more often than the 3d model engines.  Perhaps in theory better 
coding would make the outline attribute redundant.  For now, giving users the 
outline attribute gives them control.

 

Bruce

 

-----Original Message-----
From: Therion <[email protected]> On Behalf Of Tarquin Wilton-Jones via 
Therion
Sent: Thursday, 12 December 2019 04:59
To: [email protected]
Cc: Tarquin Wilton-Jones <[email protected]>
Subject: Re: [Therion] Setting -outline for pit lines

 

> You may not specify attribute -outline in case of pit.

 

Why not? It is perfectly normal for a passage to end at a pit, and that pit 
therefore becomes a line that terminates a passage.

 

I have attached a hand drawn example of how this would appear normally on a 
plan view (at least, this is how it would normally appear on a plan survey in 
the UK, such as the survey of a pothole - vertical cave - like Swinsto or 
Simpson's).

 

"-outline in" does work on the pit line here for generating a PDF. But shows a 
warning when generating LOX.

"-outline out" also works without a warning when generating LOX or when 
generating PDF.

 

What I don't understand is

 

1. Whether "-outline out" is actually the correct thing to use when the pit 
line points outwards rather than inwards.

 

2. Why it even matters which way we draw a *wall*, if "outline out"

always can pick the "correct" side to fill. Surely if it can work out the 
"correct" side of a pit line, it can also work out the correct side of a "wall" 
line, and it doesn't even matter whether the yellow tick points towards "air" 
or "rock".

 

(Having to have an invisible wall on the lower scrap makes complete sense to me 
though, since that has to have a curved wall matching the curve of the pit line 
above. This is what I already use.)

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