[Therion] vthreshold

[Xavier Pennec]

I completely agree with you that NSEW is not not a good way to measure 
the shape of about-vertical passages. In fact I personally never measure 
dimensions in NSEW directions but in the direction of the shot (or of 
the preceeding shot if it is absolutely vertical), in the reverse 
direction, on its right and on its left. I use LRUD with Up meaning in 
the (horizontal direction of the shot and Down the opposite.

As we have to give a bearing anyway for vertical shots, why not use it 
to orient the dimensions instead of a vthreshold-offset that should be 
changed for each new shot?

Xavier

Le 15/05/2012 11:04, Andrew Atkinson a écrit :
> Hello
>
> Just been play with a feature I have not used before.
>
> First It would be clearer if on p20 of the thbook the paragraph under 
> vthreshold
>
> If passages are _more_or_less_ vertical (inclination > vthreshold), 
> even UD becomes
> perpendicular to the shot – otherwise passages would not look very good.
>
> The 'more or less' is very confusing
>
> It would read better if it read
>
> If passages are _about_ vertical (inclination > vthreshold), even UD 
> becomes
> perpendicular to the shot – otherwise passages would not look very good.
>
> Also
>
> In some passages NSEW is not not always the best way to measure 
> passages, rifts on the like. So for some I have dimensions measured as 
> NW SE NE SW, possible allowing an ofset for vthreshold would be a way 
> of solving this. eg
>
> vthreshold-offset 45 degree
>
> Just a thought for the future.
>
> thanks
>
> Andrew
> _______________________________________________
> Therion mailing list
> Therion at speleo.sk
> http://mailman.speleo.sk/mailman/listinfo/therion

-- 
>  -------------------------
>  Xavier Pennec
>  Senior Research Scientist / Directeur de recherche
>  Asclepios project-team, INRIA Sophia-Antipolis
>  2004 Route des Lucioles, BP93
>  F-06902 Sophia-Antipolis Cedex, France
>  +33 4 92 38 76 64
>  +33 6 78 35 16 90
>  http://www-sop.inria.fr/asclepios/
>  -------------------------------