[Therion] 3d to QGIS - different alignment

[Andrew Atkinson]

On 20/02/2025 14:32, Bill Gee wrote:
> Hi Andrew -
> 
> What a coincidence this is!  I have been struggling with QGIS for a 
> couple of weeks.  It has a VERY steep learning curve.  I am beginning to 
> think that our future as cave cartographers will include some kind of 
> GIS work.  Some sort of tutorial would be very useful for complete GIS 
> newbies like me

I agree it is a very steep learning curve, I'm still very much on it, 
just not sure how high it is, but I'm getting to the stage I can do some 
useful stuff. I think some sort of GIS will be the front end for 
cavesurveying. Then we can concentrate on the cave data and the rest of 
the world will deal with viewing the rest of the world for us
> 
> I got your Survex plugin loaded.  That was easy.  It will open and view 
> a .3d file which is produced by Therion.  QGIS shows centerline and 
> survey stations, but no walls.  Nothing from LRUD.  I suspect that 
> Therion does not create the same kind of file as Survex.  Viewing the 
> file in Aven also does not show any kind of walls or passage polygons.

It is by no means mine, it is Patrick warren's I've done some 
modification so that it opens up the 3d file in aven. It is also ready 
to open the original data file. Currently there is a ticket so this 
information gets included into the 3d file to make full automation 
possible. Currently it assumes a one survey to one file each in their 
own directory, which works for me and many that I've delivered courses 
too, but there are many valid arrangements out there, hence needing the 
information in the 3d file.
> 
> I have struggled to get some sort of DEM file.  That is another learning 
> curve!  I have a GeoTIFF file which covers several square miles around 
> the current cave project.  The web site I got it from (USGS) would not 
> zoom in any further.  I was able to add another layer which is the .shp 
> file from Therion's ESRI output.  Also a .kml file.  Neither the .shp 
> nor the .kml file is visible

DEM is confusing, and often treated differently. The native 3d view 
handles WMS/WMTS served files but the QGIS2threejs needs downloaded 
tiles and cannot do 3D across tile boundaries. Joining tiles is a dark 
art I don't think I've mastered.


> This cave runs directly under the owner's house.  We would very much
> like to see some sort of 3D view which shows how the cave and surface
> are related.  I suspect there is only 20 feet or so between the house
> and the cave.  Not much!  The owner has some ideas for renovation
> which would reduce that, possibly to something that is not safe.

QGIS2threejs is very good. Main advantage is that it can be put on a web 
page. The native 3D view has other benefits.

This sort of thing is easy to produce once you've got over the initial 
learning curve. Happy to help, either on the list or privately, 
depending how much spam this list might want.

http://goodlife.org.uk/__Survey/LVS/

This link is likely to disappear over time.

What I really like is the ease of sending, I have multiple sources of 
data, I could do google/bing views, but need to sort the copyright 
acknowledgement. So currently you only get OSM with and without the dots 
on the surface and the 1795/1815 or there abouts map. (I need to fix the 
acknowledgements on them.)
But it has most of the tools you need, including measurement and 
transparency. Beat aven (sorry Olly)

enjoy

Andrew