But how or why would the shadow be visible if the surface it’s on is invisible? I don’t get it 
Or do you want to have that plane invisible everywhere else where it’s not shadowed but visible only where it’s shadowed?
But how or why would the shadow be visible if the surface it’s on is invisible? I don’t get it
Or do you want to have that plane invisible everywhere else where it’s not shadowed but visible only where it’s shadowed?