I have a SRTM elevation model with a point from which I would like to calculate the aproximate visibility. Using the line-of-sight tool in QGIs, I can achieve that without any difficulty. However, I'd like the tool to take in consideration the vector lines I have drawn around the point (the lines should serve as a blockage and visibility shouldn't pass through them).
Do I have to modify the raster DEM where this vector lines are (and set them to a height of 99999) or there is a way to make QGIS consider the vector lines while doing the viewshed analyses?