Interesting questions. In the the main cave I survey, we use a value (called "share") between 0 and 1 for each shot (normally we use 0, 0,5 and 1 and a very few times 0,3 and 0,7). If the the share = 0,5, means that only 50 % of the length is used when we calculate the length of the cave. The total length of the cave is therefore 24439 meters. The length of the centerline is 25703 meters. We calculate the length in Excel, and the depth in Therion.

Normally, we do not exclude any length at proper crossroads (share=1,0), meaning that we would have included the red parts in the length of the cave in the crossroad example. Our argument to do so is that a person has to walk that distance if he walks in the center of the passage. (A cave is a 3D-void and, strictly speaking, doesn't have any length, - but we humans would like to think that is has ... :-))

Regards

Torstein

Den 21.02.2012 21:17, skrev Maximillian Dornseif:

I might understand something wrong, but it seems to me, that

what is called `cavelength` in Therion is actually the length of all centerlines.

This might correspondent to the cave length in straight caves but certainly not in labyrinth like caves.

I was told about the "Kluterthöhle" in germany which was surveyed in the 60ies to ca. 5900 m and then

resurveyed and recalculated - to have only a length of 5200 m or so.

This is for on the one hand a problem with circular shots inside big rooms, like http://filez.foxel.org/3s3H0d2X361A0K222Z3N

An other problem are crossroads like http://filez.foxel.org/1t0C0r2Q011i0g1L0i00 where you can't young the shared area of two passages twice but must - at least to what I have been thought - deduct some part of the centerlines: in the following picture I have marked the parts being considered cavelength yellow and the centerlines not counting as part of the cavelength red https://img.skitch.com/20120221-jhraj625isy8j1i9naxiki3b76.png

Certainly I'm not the first person stumbling about this.

What is the preferred way to approach the calculation of cave lengths?

Regards

Maximillian
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