[Liblas-devel] Indexing for point clouds

[Hamish]

just a small argument against re-ordering data.

the raw order gives some information re. time of sample and direction of
travel for a cost of 0 bytes. if the instrument or navigation goes a bit
wonky for a short while and this is not noticed until late in the post-
processing stage (when you're pouring through the data) it provides an
efficient method or slicing out a chunk of data from a specific length
of that specific transect. if your swaths overlap and you removed the
raw order, the best you could do would to be to chop by geographical
extent, even for the swaths which overlap the region which are fine.

also anything that introduces memory or processing time overheads must
be built in a way that will scale to much larger datasets than we have
today (but might in 5 years time, when hopefully this fine library is
still in active use)



Also, I've been meaning to send a note about the C/C++ ABI stability
issues. There was a thread on the DebianGIS list about GDAL's C/C++
ABI and who should link to what. The result was that the C ABI was
heavily favoured for external apps to use even though internally
GDAL is written in C++. Maybe it is just GDAL specific -- you can read
Frank's comments at the following link, possibly it gives you some ideas
for how to handle this in libLAS.

http://thread.gmane.org/gmane.comp.gis.grass.pkg.general/1230/focus=1286


regards,
Hamish