Viewshed analysis adding polygon mitigation in QGIS?

Question

I am looking at a DSM layer in QGIS and have created a binary viewshed using the viewshed analysis plugin. I want to add a polygon layer with heights to add on top of the dsm layer to indicated mitigation and location of buildings before rerunning the viewshed analysis.

Does anyone know how to add polygons with height relative to the DSM and then complete the viewshed analysis to include them?

Answer 1

Give a z value to the polygon and then convert it into a raster with qgis raster tools. Then try to use the raster calculator to sum the DSM and the raster converted from the polygon.