There are cases where depth or stencil need to be sampled in the middle of a pass. For example, in a deferred renderrer, after the G-buffer is resolved, when the transparent objects are drawn, they may want to use the depth information in the shader in order to carefully blend with the opaque objects.

D3D12 allows creation of views that are read-only for depth/stencil, with an ability to control it separately for depth and stencil (i.e. the same alpha pass may need to mutate the stencil).

Currently, GPUTextureUsage::OUTPUT_ATTACHMENT is considered a mutating usage, which makes it impossible to sample.