In a previous question (convert-xyz-points-to-topography-and-calculate-mean-slope), I asked how to interpolate point elevation data to a raster in order to measure slope. Thus I use the Raster > Interpolation tool, and create the raster with TIN method, grid 300x300.
This works, however when I calculate slope (raster->Analysis -> DEM) it gets awful.
I have few points, but I know some softwares such as Surfer provide tools to obtain a quite smooth surface by resampling.
Is that possible in QGIS? Do I need to resample the created raster? Or is there another way to get more "continuous" slope values ?