[Therion] Vertical issue

[Bruce]

Laurent

Welcome to the list.

 

As the gradient of a survey shot increases, therion switches from the
assumption that passages are measured LRUD to an assumption that they are
measured LR-front-back and then at 90 deg to NSEW.  At present the user has
some control of this, but not complete control.

>From the therion book (and slightly rephrased by me)...

 

vthreshold <number> <units>  threshold for interpreting LRUD readings as
left-right-front-back reading perpendicular to the shot.

If passeges are near horizontal (inclination < vthreshold), LR is
perpendicular to the

shot and UD is vertical.

If passages are near vertical (inclination > vthreshold), UD becomes
perpendicular to the shot - otherwise passages would not look very good. 

In the case of vertical shots, UD is interpreted as north-south dimension
from the station to allow tube-like modelling of verticals.

 

It is the feature in the last sentence which is upsetting your output.   You
may have noticed the recent posts discussing the merits or otherwise of this
behaviour.

I have never concerned myself much with this, as my focus is cartographed
drawings, not models, so I just ignore the spurious 'walls' at pitches.
Hence this advice might not be perfect.  Try using 89.9 deg in place of 90
deg as a workaround.

 

Incidentally, does anyone know what the default value of vthreshold is?

 

Bruce

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