[Qgis-user] two items for help

[Thayer Young]

 Hi Byron,
With respect to snapping, there are several types of snapping that can be enabled, e.g. vertex, segment, etc., you also need to make sure that snapping is set for the layer you are trying to snap to. When digitizing I like to use the Snapping Toolbar (View: Toolbars: Snapping Toolbar) instead of the preferences. The left/topmost icon in the toolbar is "Enable Snapping" (a red bar magnet with white tips), make sure it is on when you try to snap, you should then see magenta squares when hovering over vertices and "x"s over segments, etc.. If you do not see these then check the layer snapping settings using the second icon from the left or top in the toolbar.  With respect to making contours, you can make a DEM from points using any of the many different interpolation tools from the different providers available in QGIS. Then from the DEM you can make contours. A good place to start is with one of the GDAL Grid tools (Raster:Analysis:Grid there are 4 of them), https://docs.qgis.org/3.16/en/docs/user_manual/processing_algs/gdal/rasteranalysis.html#gdalgridaverage
Why are there so many different Grid tools? You may want to read this about GDAL which QGIS is using for this:https://gdal.org/tutorials/gdal_grid_tut.html
After you get a DEM that you like convert it to contours using Raster:Extraction:Contour, or just change the symbology of the raster 
Note that you may also want to try the GRASS tools to do the same thing.
-Thayer

----------------------------------------------------------------------Date: Thu, 14 Oct 2021 09:41:30 -0600
From: Firstname Lastname <byron at conjugategeo.com>
To: Qgis-user at lists.osgeo.org
Subject: [Qgis-user] two items for help
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First, in settings, options, digitizing:  i have clicked on 'enable
snapping by default.'  when i am digitizing polygons, the snapping does not
seem to be engaged.  i have set the snapping tolerance to 13 pixels.  does
anyone know why the snapping does not work?  i assume that these are the
correct settings for snapping to polygons.

second.  i have imported several elevation model files into qgis.  they
come in as x,y,z, elevation points.  the original files are of the type:
GDBINDEXES, GDBTABLE FILE, GDBTABLX, and SPX.  can someone help me with a
workflow for gridding and contouring these elevation files so that they
look like either a contoured topo map or density contoured DEM.

-- 
Byron Veilleux, MSc. P.Geo
Conjugate Geologic Services Limited
Calgary, Alberta Canada
byron at conjugategeo.com
Cell:4037108414

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