[Therion] Entering survey sketch without walls

[Bill Gee]

Hi Tarquin -

Thanks for the hints and tips.  I have encountered problems with Therion 
where scraps are wider than long.  In one case I defined an invisible 
wall to close it off.

For this case, though, that will not work.  There are no passages in 
this mine.  Think of a large room in a building with support columns in 
the middle.

The limestone columns are typically 20 to 30 feet in diameter and 
located about every 80 to 100 feet.  It is FAR more open space than columns.

===============
Bill Gee

On 12/3/24 08:40, Tarquin Wilton-Jones via Therion wrote:
> Hi Bill,
> 
>> When we start doing sketch, there will be many sections that have no 
>> outside wall at all.  There will be inside wall to define the pillars. 
>> Therion has a very strong dependency on walls.
> 
> 
> If at all possible, end your surveys in passages, not at the junctions. 
> Imagine a worst case scenario, where the passages (shown here in black) 
> look like this, and this is the entire mine (case 1):
> 
> 
> ╋╋╋╋╋╋╋╋
> ╋╋╋╋╋╋╋╋
> ╋╋╋╋╋╋╋╋
> ╋╋╋╋╋╋╋╋
> 
> (Hopefully, your computer draws that as a grid of + symbols.) Always 
> start and end surveys half way down a passage, so that your days' 
> surveys look like this (case 2):
> 
> ╋╋╋
> ╋╋
> ╋
> 
> With little stub passages coming off each junction. The worst case would 
> be a very short survey that looks like this (case 3):
> 
> ╋
> 
> Let's take case 3 first, which should look like a simple + symbol. That 
> is a simple survey, just like any other cave. The walls just look like 
> this (hopefully your computer shows a simple pair of walls with open 
> ends, around the inner unshaded + symbol):
> 
> ╬
> 
> That is exactly how you would normally draw a cave.
> 
> Now the problem is that Therion might see the walls being shorter than 
> the open passage, so it might not know how to join the lines to fill in 
> the cave properly (you will see that if you enable a background colour), 
> because the walls need to be longer than the gaps at the open end of a 
> passage in Therion, for it to work things out automatically. The 
> solution to that is to draw an invisible wall across the open ends of 
> the passages. Now that will mess up Therion's automatic scrap joins - 
> which it bases on open wall ends - so I would personally use "line 
> border" with "-outline out", and make it invisible. Then the wall lines 
> can join another scrap's wall lines automatically. Make sense?
> 
> OK, on to case 2, assuming you draw it as a single scrap. That is the 
> same basic thing, but with one inner pillar:
> 
> ╬╬╬
> ╬╬
> ╬
> 
> So you just set that inner pillar's wall to "-outline in", like you 
> normally would for an oxbow.
> 
> Case 1 is just case 2 with more inner walls.
> 
> Hopefully that makes sense.
> 
> The main thing for you, is to remember not to end your surveys at a 
> junction, or you will hate yourself later when you get all the unpainted 
> holes between your surveys (which have to be fixed with some invisible 
> walls and a lot of manual line joining). End it *before* or *after* the 
> junction.
> 
> Let me know if that needed clarification.
> 
> Tarquin
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