Hi Ben -

The data file I refer to is a Compass file containing centerline and LRUD data 
from the cave.  It is not from either Therion or Survex.

In this case the cave is very small, only 50 meters, and there are only 14 
survey stations.  Retyping it into a Compass data file did not take long.

Compass and MeshLab do very different calculations to come up with volume.  For 
my cave Compass gives about 2900 cubic feet and MeshLab gives over 20,000 cubic 
feet (about 585 cubic meters).  Compass is doing a simple calculation based on 
polygons and using only centerline plus LRUD.  MeshLab is a much more complex 
calculation based on a 3D model of triangles.  Ultimately its calculation can 
be traces back to centerline, LRUD, walls, passage height objects and cross 
sections.  Therion uses all of that to build a .lox file which, through 
translations, becomes the MeshLab file.

========
Bill Gee


On Saturday, January 29, 2022 3:42:33 AM CST Ben Cooper wrote:
> Hi Bill, Torsten,
> What is that file; is it a standard output file from Therion or Survex?
> Best regards
> Ben
> 
> Sent from my iPhone
> 
> > On 28 Jan 2022, at 12:57, Bill Gee <b...@campercaver.net> wrote:
> > 
> > Ha!  Torsten, you are a magician.  Thanks!
> > 
> > That was indeed exactly how I calculated this.  I had completely forgotten 
> > about it.  Fortunately the data file still exists on my Windows virtual 
> > machine, and Compass produces the number I need to defend.  I now know how 
> > to reproduce the calculation.
> > 
> > Breathing a huge sigh of relief ...
> > 
> > ========
> > Bill Gee
> > 
> > 
> >> On Friday, January 28, 2022 6:40:00 AM CST Torsten Schnitter wrote:
> >> Hi Bill
> >> 
> >> May be you are looking for this ... !?
> >> 
> >> cheers,
> >> Torsten
> >> 
> >>> ---------- Ursprüngliche Nachricht ----------
> >>> Von: Bill Gee <b...@campercaver.net>
> >>> An: therion@speleo.sk
> >>> Datum: 14.08.2019 23:38
> >>> Betreff: Re: [Therion] How to calculate the volume of a cave
> >>> 
> >>> 
> >>> Update:  After poking around a bit, I discovered that Compass will 
> >>> calculate cave volume based on centerline and LRUD data.  Doing that 
> >>> means I have to run a Windows computer (ugh!) and type in the survey data 
> >>> twice (double ugh!)  Fortunately the cave for which I need this is small.
> >>> 
> >>> Can this feature be added as a suggestion for future versions of Survex?
> >>> 
> >>> Compass does quite a few other calculations.  For example, it will 
> >>> calculate the volume of the bounding box.  A sample report is attached.  
> >>> It is nice that the report is in both meters and feet.
> >>> 
> >>>> Hi, I am also interested on volume calculation!
> >>>> 
> >>>> Please keep me updated it!
> >>>> 
> >>>>> On 11 Aug 2019, at 22:22, Benedikt Hallinger <b...@hallinger.org> wrote:
> >>>>> 
> >>>>> It would be awesome if the compiler could derive this fron the loch 
> >>>>> model and write it to the statistics block (the one where also loop 
> >>>>> closure info and total west/east and north/south dimwnsions are 
> >>>>> returned) when compiling this, as the neccessary data should be already 
> >>>>> present?
> >>>>> 
> >>>>>> Am 09.08.2019 um 14:58 schrieb Bill Gee <b...@campercaver.net>:
> >>>>>> 
> >>>>>> Hello everyone - 
> >>>>>> 
> >>>>>> What tools can be used to calculate the volume of a cave based on 
> >>>>>> center line and LRUD data?
> >>>>>> 
> >>>>>> I found an email from Martin Sluka from about 4 years ago describing 
> >>>>>> how to use Loch to export a .lox file in other formats, then run that 
> >>>>>> file through CloudCompare or ParaView.  The process looks very complex 
> >>>>>> to me, and besides - Loch does not run on my computers, so there is no 
> >>>>>> way for me to generate an export.
> >>>>>> 
> >>>>>> As far as I can tell, Survex does not have a way to calculate volume.
> >>>>>> 
> >>>>>> Could it be done with a KML file and Google Earth?
> >>>>>> 
> >>>>> _______________________________________________
> >>>>> Therion mailing list
> >>>>> Therion@speleo.sk
> >>>>> https://mailman.speleo.sk/listinfo/therion
> >>>> 
> >>>> _______________________________________________
> >>>> Therion mailing list
> >>>> Therion@speleo.sk
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> >>>> 
> >>> 
> >>> _______________________________________________
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> >> 
> > 
> > 
> > 
> > 
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