Hi
unfortunately its impassible right now.
When I needed to do that, I created a DEM raster based on my buildings contours. then I use viewshed as is.
Or- you can build a model that using multiple line of sight to asses where is the area that is not visible.
for my opinion it is very strange that this options not exist since it's actually working with shadow calculation, so why not to use it for other stuff?
