[Therion] Spikes and shadow passage in Loch output

[Stacho Mudrak]

Quoting Stelios Zacharias <stelios.zacharias at selas.org>:
> The cave is split into two scraps, although I do not think this is 
> causing the problem. The first difficulty is the appearance of a 
> shadow passage, in the south and west of the diagram. The passage 
> should be in the blue zone for depth, but there is a high echo and a 
> sloping line unconnected to either the high echo or the actual 
> passage. The scrap border is at the meeting point of the three.

This is because there are no survey stations with known Z coordinate in these
parts of your scraps - therefore therion is not able to determine "altitude" of
these parts and they are therefore in some average scrap altitude (obviously
wrong in this case). If you will add station points with corresponding names to
your scraps, they should be placed in correct altitude.

> The other problem concerns spikes either upwards or downwards which 
> appear usually in chambers. Two examples of this might be seen at the 
> far eastern end of the survey.

Hmmm, this is a known bug, that happens if single scrap goes over multiple
altitude levels. Splitting cave into multiple scraps within single altitude
level usually helps in this case, but it is still a bug that needs to be fixed.



> If the .th and .th2 files are needed for investigation, I would be 
> happy to send them.

This would help me to find out, where the problem is. Last time I was trying to
fix this on Wookey's 80km mulu scrap and obviously - this was not possible. So
some small cave where it appears is welcome.

Regards, S.