Hello, I think I understand all of the code in lesson 27, but I still have a question about how its working exactly. I believe I understand what the 2 passes of mapping the shadows into the stencil buffer are doing - the second pass eliminates what it overlaps with from the first pass to dispose of any "floating" shadows(I mean pieces of the first quads that aren''t projected onto an object and just in empty space)I think. What I''m wondering however is why does this work so well - is there a way to show mathematically how this works out so perfectly, because it doesn''t seem that intuitive to me - I would think that the back facing visible quads wouldn''t overlap the front facing visible quads so perfectly and there might be remenents of the front quads from the first pass left in the stencil buffer that would cause "floating" shadows. Thanks for any comments!