Blender Git Loki

Fix T86037 EEVEE: SSR option changes render passes result

This was caused by the SSR option resetting the accumulation. But the
render passes were only cleared in the init phase. This means that
when SSR was resetting the taa_render_sample the actual renderpasses
would still contains 1 sample. This means the renderpasses were always
divided by the wrong number of samples.

The fix is to clear just before accumulation if the sample is 1.

The fact that it works for motion blur is kind of a blessing. This is
because we check stl->effects->ssr_was_valid_double_buffer before
resetting the sampling. So this only happens on the first motion step
and does not affect the rest of the rendering.

Reviewed by: jbakker

Differential Revision: https://developer.blender.org/D11033