Incorrect precomputed visibility data

Hi, my scene consists of a floor on top of which there is a cube wall and a sphere behind the wall. I build the lighting and get the precomputed visibility data. I am running in Debug Editor mode so that I can inspect all the variables properly. I have two questions:

  1. Looking at the code, it seems like View.precomputedVisibilityData is an array of 8-bit integers, where each bit corresponds to a static mesh. Bit is 1 if visible else 0. Is my assumption correct ?

  2. I put a breakpoint in such a view such that the sphere is completely occluded by the wall. But when I look at View.precomputedVisibilityData (in memory view), it is holding 15, which means all the meshes are visible. If my first assumption is correct, at least one bit should be 0 right ?

I’ve attached the view. Please note that I’ve turned on ‘visualize occluded primitives’, so the green box denotes the sphere which is occluded. Am I missing something ? Can someone explain if I am making the right assumption and looking at the data correctly ?

Thanks