What's the best way for creating a g-buffer? Most of the documentation I've read suggest rendering the scene geometry normally and then writing to multiple render targets. A drawback to this method is that render targets have to be in the four 32-bit value format. This could waste memory space and bandwidth if you're not writing a multiple of four 32-bit values. Also, it restricts the geometric data alignment to single rows (where each row starts at xmin and increases to xmax with the same y value), when small tiles might be better for coalesced memory access later on in a compute shader.
Is it a better idea instead to write to a structured buffer? How would you go about doing the depth testing to ensure that the final value written into the structured buffer is actually on top? I would think one method would be to explicitly read the depth buffer, compare the values, then write to both the depth buffer and g-buffer if the test passes. The other option would be to define the earlydepthstencil attribute so that only fragments that pass the depth test can invoke the pixel shader (which writes the value to the g-buffer). Does this actually work? Are there major setbacks to this method?
