[Therion] Big room multiple scraps - How to join

[Bill Gee]

A couple of very interesting ideas here.  I tried them out this morning 
on a small test cave.  I will have to think about this for a bit to see 
how it might be useful.

My small test cave has a total of about 80 feet of passage.  There are 
three scraps which come from background sketch on two different sheets 
of paper.  The same sheets also include profile and cross-section sketches.

The first thing I did was Tarquin's method of creating a single .th2 
file.  Creating the file was easy - just adding another export line to 
the thconfig file.  It produced a valid .th2 file which has all objects 
from all scraps.  The joins were already performed.

There was no background image, so adding anything to this would be a 
matter of eyeballing it.  I don't think there is any way to add a 
background image that would make sense.

The second thing I did was review Marco Corvi's documentation at the URL 
Tarquin provided.  The new thing I learned is that backgrounds can be 
assigned to scraps as well as the drawing area.  With my test cave I 
added background to the three scraps, added the appropriate export line 
to thconfig and then compiled.

In the map editor I then started a new .th2 file.  I imported the .xvi 
as the drawing area background.  It came in.  I can see where all three 
sketches were apparently overlaid.  There is a nice centerline for the 
entire cave.

The problem is the sketches are not transparent enough to use.  The only 
part of the sketch that has any visible drawing on it is for the last 
scrap mentioned in the map statement of the .th file.  The other 
drawings are not visible.

The result file can be seen at

https://campercaver.net/MiscFiles/test.xvi

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

On 8/3/23 15:13, Tarquin Wilton-Jones via Therion wrote:
>> Something along the lines of
>> map ProblemchamberMP
>> GrandcanyonSP
>> FlatroomSP
>> endmap
>>
>> select Problemchamber
>> export map -proj plan -o Problemchamber.th2
>>
>> Instead of exporting to pdf, this will then export this to a .th2 file,
>> where I guess it will appear with all the lines you have joined, instead
>> of you having to join them with line joins/scrap joins or amending line
>> end positions to force therion to automatically recognise them.
>>
>> This will allow you to work on the whole chamber as one in a single .th2
>> file.
> 
> Fun fact, you can even ask therion to take the sketches, and output
> those, pre-warped and pre-scaled, aligned to each other. It's fairly
> advanced stuff though, and I only used it once while boggling slightly.
> 
> Sketch Morphing, in the Therion book. Or here:
> http://marcocorvi.altervista.org/caving/tbe/m_04/m_045.htm
> 
> That's harder than the original problem, but very cool if you wanted to
> use it, since it can solve this exact problem (multiple surveys of
> different arts of the same chamber at different scales).
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