Well, how is luminance calculated using a FP16 RT? I am thinking one would do it the same way, but HDR pixel luminance attributes would be recorded just before the tone mapping is done as last step in the shader, followed by writing to integer buffer.
ERK
PS. I guess I was thinking that luminance could be "integrated" as each pixel is rendered, to a single global value, not to another RT.
ERK
PS. I guess I was thinking that luminance could be "integrated" as each pixel is rendered, to a single global value, not to another RT.