Hi SPDlib folks I’ve just started to tinker with SPDlib, with the aim of working out how to use point clouds as a data service - this example:
https://spectraldifferences.wordpress.com/2014/08/06/dem-spdlib/ …is pretty representative of what we want to do - get non-specialist users to be able to work with point data we currently hold, and will hold in future. I wonder - has anyone tested the limits of SPD yet? I’m right now attempting to prepare an SPD file with 400 million points, which replicates a postgres-pointcloud database and a set of flat netCDF files with the same dataset. I’m having a ‘fun’ start with SPD, it’s currently quite a mess - I’ve got a functioning v3.3, following Daniel Clewleys instructions just posted (conda create -n spdlib_v3_3 -c osgeo -c rios -c conda-forge spdlib=3.3.0). …and then see how well SPDlib functions for point retrieval and doing useful jobs with data subsets. It’s been used for Australian data before, but for only small blocks. We need to get much bigger! To do so, I’m actually working on the some of the same data as Narsimha, but with a slightly different focus. And here’s my first result: spdtranslate --if LAS --of SPD -b 10 -x FIRST_RETURN -i ACT2015-C3-ELL_6886094_55_0002_0002_l13.las -o ACT2015-C3-ELL_6886094_55_0002_0002_l13.spd ------------- 1.5G /mnt/vol1/pointcloud-data/ACT_Lidar_8pt/Ellipsoidal/las1.3/ACT2015-C3-ELL_6886092_55_0002_0002_l13.las 975M /mnt/vol1/pointcloud-data/ACT_Lidar_8pt/Ellipsoidal/las1.3/ACT2015-C3-ELL_6886092_55_0002_0002_l13.spd (blocksize choice is quite naive, data are ~8pt/m - I’ll investigate what is in the blocks tomorrow :) ) …so a slight storage improvement, and now it’s indexed as well! Anyway - that is a distraction. I’d like to hear what experiences people have with properly large point clouds. So far it’s chewing up a lot of memory converting relatively small datasets (~90 million points, without pulse data) to spd, and I’d like to scale up to many hundreds of millions to billions of points. Also, is there any benefit at present to going through a ground up SPDlib 1.4 installation? Cheers Adam ps - if anyone is going to FOSS4G in a few weeks and is happy to talk about SPDlib and huge datasets, drop me a line off list - it would be great to see what other organisations are up to. -- Adam Steer Earth systems data service specialist National Computational Infrastructure Leonard Huxley Building, Mills Road The Australian National University Acton ACT 2600 Australia adam.st...@anu.edu.au +61 2 6125 1413 http://nci.org.au ------------------------------------------------------------------------------ _______________________________________________ spdlib-develop mailing list spdlib-develop@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spdlib-develop
