[Done] Pertaining to the articulation of CC with GIS

[Dimitri]

Hi Daniel,

during an international summer school, we used a lot CC to process airborne and terrestrial lidar data and subsequently other tools outside CC (CANUPO, M3C2, matlab, ARCgis). While supervising the students I thought of a few things that will help a lot people working on data with national grid coordinate (NGC)(i.e. big numbers) and to speed up the connection between CC and software working on 2D raster data (ARCgis):
. it would be great if the user could store a series of translation (in some kind of user_config external file that could be used on different PCs). When CC would open a file and suggest a translation, the user could choose directly from a list of preexisting translation (that CC would have picked in this user_config file) for a given area rather to enter manually the numbers for X Y Z. Just a name with the translation would be enough (e.g. Mt St Michel +52303200 +23232424 0). During the practicals, we spent a lot of time reentering manually the exact same translation parameters to various datasets (with risk of manually entering incorrect numbers....).

. There's one option missing (or I could not find it): when you load NGC data, CC offers to shift the data (ok) and keep the info on the translation in the object properties (great). However, I did not find a way to save the data without the translation. The translation is always applied back when saving the file. That would be extremely useful if someone wants to use an excerpt of the data in local coordinates in another software that does not have the translation option (i.e. CANUPO, M3C2 ;-). I've tried to duplicate the file (but it keeps the translation info), or to manually apply a transformation which would counteract the translation but somehow it did not work (I don't remember precisely why...). This could be a new function called "export" (rather than save) in which you would have two tick boxes: 1 : export without shift, 2 : apply a shift during export. The second option is necessary to apply a shift back on local coordinates data that need to be stored in NGC. You could pick directly transformations in the user_config file

. Also when picking the transformation to the center of the cloud, by default I think you should not change the Z coordinates as it's (normally) never going to be larger than 7000 m;-). it's generally useful to keep the true absolute elevation (especially to generate color coded evelation).

. And finally, the last bit of thing that is missing to seamlessly integrate results from CC into GIS software would be the implementation of the GEOtiff format during the projection grid export. That would be really, really great. Sure, there's the x,y,z but geotiff is read by many apps and is much more compact. I think it's in the GDAL library so should not be too difficult to implement.

Thanks

Dimitri

[daniel]

Hi Dimtri,

1) Indeed, we could say that CC will look for a particular file just next to the program executable (let's say "global_shift_vector_list.txt" or equivalent, with 4 columns "Name, X, Y and Z"). If it finds it, then it will fill a combo-box with the corresponding entries. Should be not too hard. I'll add this to the TODO list if it's ok with you?

2) In fact you can edit the shift information now (see Edit > Edit global shift). So you can change it, remove it, add a new one, etc.

3) Indeed!

4) Not difficult to implement, but difficult to integrate with CC ;) I already tried it (on Windows) and I was not very pleased with something (don't remember what exactly now). I should take a second look.

[Dimitri]

Hi Daniel,

1) that would be perfect !
2) Arrgh, I should have seen that. That's great !
4) ah, a little challenge then ;-)

Thanks for the feedback !

Dim

[daniel]

Finally, the 1st point is done! (sse http://www.danielgm.net/cc/forum/viewtopic.php?t=872).

And the 4th one was done a while back by the way ;).