I am seeing erratic LRUD results at many stations when I use Data/Calculate/LRUDs. Can you please inform how the LRUD calculation is made? I want best possible LRUDs so that Visualisation/Volume displays can be made without anomalies. Thanks

Hi Jorchen,

As you know, I do loads of splays to the point where LRUDs are pretty much meaningless to me. However, I still acquire LRUDs just after my station to station shoots, because they improve flagging a station change in a massive amount of data lines in case Topodroid missed an change of station (i.e. 3 similars shoots). I also acquire them to make sure I have the LRUDs I want in case I go for a simplified version of the volume. Splays acquisition strategy can be very different from LRUDs. I always have many splays that reach walls far beyond the next/previous stations or even several stations. This allow me to enhance the characterisation of the volume as well as ensuring that the data are consistent. By doing this, magic LRUDs become an awkward tool to use as it will use all the splays, and not only the one likely to be LRUDs.

I see 2 improvements that could be made:

1 - magic LRDUs only use splays within 4 cones (Left, Right, Up, Down) based on the LRUDs mode selected (0,1,2,3,-1,-2,-3) for its axis direction and a setting defining the cone angle (+/- 15-20° by default?). Any splays out of these cone volumes should be disregarded for LRDUs calculation.



2 - add an option in the LRUDs mode column to define which splays to use as LRUDs (L,R,U,D). This could improve the volume rendering, as it would provide slope and direction to selected LRDUs.

hmmmm... maybe the cone angles were too large.

sounds like a good option.

what do you think of my second option... pickable LRDU?

sounds like a good option. I guess this could be applied to "profile" as well as if all splays are displayed, the profile can be far away from the results we are looking for.

what do you think of my second option... pickable LRDU?

The idea would be to use the already existing column "LRUDs". My suggestion is not to create classical LRDUs from the Magic LRDUs feature selecting the 4 columuns. The idea is to define 4 splays as LRDUs. then LRDUs can be based on their actual length, azimut and inclinaison and match what the surveyor thought would be the best measurements to render the cave volume. I'm sure this would improve the Volume display, primarily in side-way slanted galeries, as classical LRDUs only works well in tubic galeries or pits.