I would like to know which steps I need to take right now. I presume it would be better to transform this into a raster, right? So I can give each pixel a value (in this case, 12 different values) and after that, continue with r.walk and so on.
If so, do I need to merge all these 12 files into one? Can I transform this into a raster while still keeping each of the different categories? (including the line vectors?)