Hi Diego Can I suggest to put your post in a new thread instead of incorportating it into an existing (and unrelated to your post) thread? I suspect many people who may have given you feedback will have missed your message unless they were following the sextatnte testdrive discussion.
Regards Tim On Sat, Apr 20, 2013 at 4:12 PM, Diego Gnesi Bartolani <[email protected]> wrote: > Hi, > > I am an italian archaeologist and an enthusiastic QGIS user. I do > what I can to spread the knowledge about QGIS and other open source > softwares to my university students (I am a contract professor at the > Basilicata University and some days ago I've become contract professor > at the Specialization School of Archeology of Udin, Venice and > Trieste). > The main difficulty I have with open source GIS is the advanced > editing of vector layers. QGIS doesn't offer too much support to > digitizing, the CAD Tools plugin has some useful functions but is far > from being complete and the kind of interaction that it proposes is > not very productive and time-saving (it's not a critic: CAD Tools > saved my life a lot of time, and I want to thank the developers and > maintainers). Many times, I had to convert my vector layers to dxf and > back in order to perform some complex tasks (with all kind of > conversion problems, like the preservation of the attributes values, > etc.). > I have some experience in programming (about ten years of > developement, mainly in C# with the .NET Framework, before I switched > to Linux), and I would like to try (only try, without promising > anything!!) to implement complete CAD tools and functions (I there > isn't and analogous project already active; in that case, nevermind!). > > I think that developing a CAD plugin from scratch is very hard to me > and maybe not the better way to get good results, so I'm oriented to > try to augment the interaction between QGIS and an existing CAD > software (I'm thinking to LibreCAD). I thought to two possible > strategies: > > 1. Use the LibreCAD library and source code to develop a C++ QGIS plugin; > 2. Create a shapefile/spatialite/postgis driver for LibreCAD in order > to edit those formats inside LibreCAD. > 3. Convert some layers of the QGIS project in a dxf file and back > (each QGIS layer in a different layer of the final dxf file). > > I'm asking your opinion about which of those ways could be the faster > or the better to implement, or which one is impossible to undertake > according to your knowledge of the QGIS API. > > My doubts are: > > Strategy #1: Probably the ideal one, but does the implementation of > complex snaps or constraints against the features of other layers > (i.e. midpoint, parallels, etc.) require changes to the QGIS API, or > all these operations can be contained on a plugin? Is it better to > work directly on QGIS vector layers or to create a plugin layer, edit > it and then commit the changes to the vector layer? The conversion > could help me to manage geometries in the way LibreCAD wants. Is it > possible in your opinion to have an interactive shell (i.e. draw the > first point, and then inserting the coordinates of the second point)? > Strategy #2: Probably the easier, but I should find a way to disable > some LibreCAD functions (i.e. the drawing of splines, or the drawing > of points on a line layer) without disseminating my changes all over > LibreCAD's source files. For this kind of solution I'll ask to the > developers of LibreCAD. > Strategy #3: The problem is on committing the changes of the dxf file > to the original layer: how to specify that a line in the dxf file must > replace the geometry of and existing record of the original spatialite > layer? Maybe it's impossible, it doesn't seem to me that I can put on > a dxf file the necessary metadata to preserve a link to the original > features. > > What do you think? And what do you actually do when you have to draw > complex shapes on shapefiles or other vector layers? > > Diego Gnesi > > 2013/4/20 Paolo Cavallini <[email protected]>: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> Il 20/04/2013 10:52, Victor Olaya ha scritto: >> >>> I have been thinking about changing all the options dialog. Doesn't >>> look hard to do, so you can count on having this ready soon >> >> great, thanks. ready to help if necessary. I still think the appearance of >> sextante >> dialogs do not seem too much in line with QGIS look, so maybe you can ask >> someone to >> help with the GUI. >> >>> 1) The classification of algorithms is done manually...and it is >>> boooooring to do :-) SAGA and QGIS ones are already done, but I have >>> to do the GRASS ones. However I am not sure about including GRASS, it >>> is more complex to use. You can use a SAGA algorithm without knowing >>> what SAGA is, but to use a GRASS one, you need to understand some >>> GRASS ideas, so it is an advanced process, and the simplified >>> algorithm classification shouldn't assume that. You can always change >>> to the advanced view to use GRASS (now you can change directly from >>> the toolbox, no need to go to the config dialog) >> >> Sorry I do not agree with you: >> * most GRASS commands, as they are incorporated into sextante (or in the >> GRASS >> plugin, by that way) are really straightforward to use; in courses people >> often do >> not notice the difference >> * more importantly: GRASS is included in most if not all QGIS installation, >> so you >> can rely on it; this is not the same for SAGA >> * GRASS modules have a proper manpage, while SAGA is sometimes very hard to >> understand >> * GRASS has a long history and a wide community, so you can trust more on it >> on the >> longer term. >> So in short I would not put GRASS as a second class citizen in Sextante ;) >> >>> 2) I would like to have in that list, only those algorithms that >>> need no extra configuration, to make that the default and have it >>> working out-of the box. That's why R and OTB, for instance, are not in >>> there. >> >> Again, do not agree: some OTB commands are very straightforward, and solve >> problem >> people have struggled on for years. The usual effect of showing it is >> jaw-dropping. >> Removing stuff from first sight may have deeper consequences than a clever >> developer >> can foresee, sometimes :) >> >>> good idea. If OTB goes into osgeo4w, I could add the OTB algorithms to >>> the simplified list of algorithms >> >> OTB *is* already on osgeo4w - my suggestion (a strong one BTW) is to include >> it in >> the standalone installer for QGIS 2.0 >> >>> I still have to send Jurgen the SAGA package as we discussed it in the >>> Hackfest. We can put both SAGA and OTB, and taht would really give a >>> lot of power to SEXTANTE >> >> Right! >> Thanks for your hard work, and good code. >> - -- >> Paolo Cavallini - Faunalia >> www.faunalia.eu >> Full contact details at www.faunalia.eu/pc >> Nuovi corsi QGIS e PostGIS: http://www.faunalia.it/calendario >> -----BEGIN PGP SIGNATURE----- >> Version: GnuPG v1.4.12 (GNU/Linux) >> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ >> >> iEYEARECAAYFAlFyZ5QACgkQ/NedwLUzIr7T1ACgsRbc0ZwCb0SHsfj++uGUVN2+ >> /6QAoLUqOAhrTP1Rho0PWYfPVVzjyQJr >> =cHRR >> -----END PGP SIGNATURE----- >> _______________________________________________ >> Qgis-developer mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/qgis-developer > _______________________________________________ > Qgis-developer mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-developer -- Tim Sutton - QGIS Project Steering Committee Member (Release Manager) ============================================== Please do not email me off-list with technical support questions. 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