contourgeotiff-tiffqgisterrain
I need to quickly create a TIFF terrain (shades of grey terrain) from contour lines, or rather to create a GeoTIFF. In the past, I extracted vertexes from the contour lines and used that to create new contour polygons and used that to create TIFF. But this takes a lot of time and a lot of steps.
Is there a way to do this quickly?
I've experienced the same problems you area having in your second method. I exported a Raster to a Vector and try to and use v.generalise and I get mostly smooth polygons with the occasional 'stepped' boundary which appears to have been unaffected by the algorithm.
I found a process that worked for my task, not sure if its the best way but thought i'd share it in case it helped you.
What I started with was an ascii grid from BoM that looked like this:
What I wanted something similar to what BoM produce like this:
I was able to get to an outcome (that I was happy with) using the following steps.
After styling my output is below:
I would also be interested in hearing if someone knows a simpler way. Originally I was thinking similar to @Rx_ that I could just convert my raster to vector then generalise and I would be done. What I had to do was much much longer.
It sounds like you have the original surface model so to identify the depressions use a sink algorithm. Here is a link to filling sinks using QGIS.
I have not used this tool in QGIS, only something similar in ArcGIS so I am not sure of the output. In any case, you could subtract the sink output surface from the original surface. Any greater than zero pixel would be a depression.
Best Answer
Use v.surf.rst
An immediate solution which comes to mind is using
v.surf.rst, which is a GRASS module accessible via theProcessing'->Toolbox`It takes the vector contour layer as input (you will neet to choose the file, as it does not look into currently loaded layers), and produces an interpolated raster, with the desired pixel size.
https://grass.osgeo.org/grass78/manuals/v.surf.rst.html
TIN Interpolation
Another viable option is
TIN Interpolation, also accessible via theProcessing'->Toolbox`.In this case, Iw ould suggest the "linear" option: