[Therion] Joining maps with the join command

[Tarquin Wilton-Jones]

Hi,

I am currently learning how to use Therion to draw up a detailed survey.

My survey is split into several "caves", each of which has its own .th
and .th2 file. In the .th file for each cave is a separate "map", so
that the cave can be rendered separately.

cave1.th:
survey cave1
 input "cave1 plan.th2"
 input "cave1 ee.th2"
 map cave1MP
  scrap1
  scrap2
 endmap
 centreline
  ...
 endcentreline
endsurvey

cave2.th:
survey cave2
 input "cave2 plan.th2"
 input "cave2 ee.th2"
 map cave2MP
  scrapa
  scrapb
 endmap
 centreline
  ...
 endcentreline
endsurvey

Then I have an overall file which combines the maps called allcaves.th:
survey allcaves
 map allcavesMP
  cave1MP at cave1
  cave2MP at cave2
  join ____________
 endmap
 centreline
  ...
 endcentreline
endsurvey

Imagine the two caves join in scrap1 (id "foo":0) and scrapb (id
"bar":end), and I want to use a join command to make the scraps join
neatly (I have already positioned the passage ends very close to each
other). Could you please tell me the syntax needed to make the join
command reference the correct points of the correct lines inside the
correct scraps inside the correct maps?

Every example of the "join" command I could find assumes you were trying
to join scraps inside the same map, and did not show how to reference
items in a sub-map. As a result, I have not been able to work out how to
construct a valid join command for this situation.

Many thanks for any information you can provide.

Tarquin