I haven't used tiled resources yet, but I think you have to perform calculations that depend on the tiled resources' address mapping model on the CPU, and send the results to your shader, treating them as relative to the start of the region of active tiles. Also, I think that the RWByteAddressBuffer you access in your shader is not actually the whole buffer, but only the active tiles, so the RWByteAddressBuffer's address 0 actually corresponds to the tiled resource's pDestTileRegionStartCoordinate value set with ID3D11DeviceContext2::UpdateTiles, and RWByteAddressBuffer::GetDimensions returns only the size of the active tiles...
Also, there's no such thing as a negative uint.
Hey thanks for the reply. You're right about uints not being negative... that was silly of me. I wrote that because I was storing the values and reading them back on the CPU as integers. Regardless though, the returned values are incorrect once the tiled resource RWByteAddressBuffer is larger than what can be addressed with a 32bit uint.
With tiled resources though, indexing into buffers remains the same. If you hit a sparse area though, the behavior will differ depending on the "tier level": supported by your GPU. In my case, I map a single "dummy" physical tile to any sparse tile of the buffer. Though inefficient, any time a store occurs to a sparse area, it will map to the dummy tile.
I'm pretty sure the code is correct since I tested the kernel on a smaller buffer. The problem is that the API allows you to create really huge tiled resources (since memory isn't allocated until you actually use UpdateTiles(...)), but doesn't let you access areas of byte addressable buffers that are beyond 2^32 bytes. The only solution I currently see is to either bind multiple buffers to the kernel and implement some sort of logic that would spill over to the next buffer once you reach areas that are addressable or rethink my algorithm as a whole .