I’m curios if there is a software able to create vector map outline from cloud data automatically.
Martin Odesláno z iPhonu 19. 6. 2019 v 23:13, kevin dixon <[email protected]>: > Nick, > > I have both DistoX2 and LiDAR data for parts of the same cave. > > All the LiDAR scans were registered to create a single model as normal > for LiDAR. > The individual scans were then decimated in the Point Cloud Software > using a suitable distance to nearest neighbour. I found Survex gets a > bit overwhelmed with millions of LiDAR data so you may have to > experiment with a suitable distance between adjacent LiDAR data. Each > decimated individual scan was then output to LibreOffice Calc and new > ranges, bearings and inclinations calculated to create single station > Survex files with lots of splays, now all orientated the same way. > Dummy traverse observations were created within Survex to link all the > LiDAR scan stations based upon the Point Cloud registration > coordinates and elevations of the scan stations. > I then manually matched the Survex output of the above LiDAR data to > some known DistoX2 observations or in your case, perhaps known show > cave outline. You can do this within Survex by having your non-LiDAR > data as another survey then using a Calibrate Compass figure (may > require up to +/-180degrees) within the LiDAR Survex data to change > the orientation so as to match the known and also setting one of the > LiDAR stations within the Dummy traverse observations to coordinates > and elevation that give a good fit with the known data. Several > iterations are needed with these. > > Hope that is self explanatory. > Has worked for me - I have a DistoX2 Survex model with very detailed > LiDAR data in two large chambers - the resulting LOG file looks a bit > weird eg. > 1 8659-node. > 1 19071-node. > 1 21844-node. > 1 22774-node. > 1 23053-node. > 1 24470-node. > 1 25278-node. > > As a side note, part of my project includes a Show Cave and I have not > had a problem with insitu metalwork there or on scaffolded sections of > the cave. I have always kept the DistoX2 well away from metalwork and > when the passage is narrow with metalwork, I have used an intermediate > station with DistoX2 observations to it only, never from it. > I have considered the use of turned angles to get through a serious > metaliferous section - the Leica DST360 could do this for you or a > small theodolite - use magnetic obs at each end to orientate it all. > > Kevin Dixon > >> On Wed, Jun 19, 2019 at 9:02 PM Nick Bairstow <[email protected]> wrote: >> >> Hi, Something a bit different for the clever people out there. >> >> >> >> I have been playing with some 3d scan data and have attempted to use it to >> create a Therion map. >> >> Firstly we put created an outline of the cave passage using point cloud >> software and exported as dxf. >> >> I turned the dxf into a background sketch and drew around it and could >> output a nice pdf of our cave. Also did a manual scaling. So far so good. >> >> >> >> I added a dummy station and gave it entrance coordinates, then exported as a >> KML model. When I open the output file Google Earth fly’s to the correct >> spot and shows a pin with the cave name but no cave. >> >> My question is , does this fail because we have no survey data, centreline >> etc and it is impossible to do this or am I missing something. >> >> >> >> As an alternative I can export to an esri shp file and run that though Qgis >> and get what I want but as I am going to attempt to combine the 3 scan data >> with a several normal disto surveys I would like to see Therion Kml output >> work if possible to save lots of messing around. (GIS makes my head hurt) >> >> >> >> On a side note using the point cloud software I can slice though the scan >> data on different planes and pick up lots of detail, rocks and boulders etc. >> Using the dxf/background image method I should be able to get a very >> accurate representation of the passage. I can hear you all saying what the >> hell is he doing that for when he could just survey the cave in the normal >> way! Well the cave is a show cave and absolutely rammed with metal walkways >> and cables. Disto tests showed wild inaccuracy’s so it was looking like the >> only viable option was going to be to use a Total Station device which we >> don’t have. We then had a very kind offer to scan the cave, this has proved >> to be very interesting but drawing a normal map is a bit of a challenge >> although it seems not impossible. >> >> >> >> Any help would be appreciated. >> >> >> >> Nick >> >> >> >> _______________________________________________ >> Therion mailing list >> [email protected] >> https://mailman.speleo.sk/listinfo/therion > _______________________________________________ > Therion mailing list > [email protected] > https://mailman.speleo.sk/listinfo/therion _______________________________________________ Therion mailing list [email protected] https://mailman.speleo.sk/listinfo/therion
