I'm using QGIS 3.16. I am trying to do the following: Starting with a DTM model (geoTIFF format) I am computing the contour lines (100m) with QGIS. So far, so good. In order to import the results into Adobe Illustrator I am trying to use the Vectorize (Raster to Vector) tool to obtain the same result in a vector format. However:
- when I try to save the contour lines layer in QGIS from the original DTM layer, the resolution is very poor (and when saving there doesn't seem to be an option to increase the resolution), i.e. much worse than if I just take the original DTM layer and choose the contour option to display the desired contours.
- I can start the Vectorize tool with both the original or the saved contour line layer but it computes indefinitely (I let it run for 2-3 days) without returning a result (but no errors either).
Any advice for a novice GIS user on how to obtain contour lines from a raster DTM in a vector format (any standard format is fine, e.g. shapefile)?