https://bugs.freedesktop.org/show_bug.cgi?id=70327
--- Comment #1 from tony.wasserka@dolphin-emu.org --- ...cf. first attachment "Full rendered scene with bug visible". Second attachement "Full rendered scene with software renderer" shows the same scene rendered properly with "LIBGL_ALWAYS_SOFTWARE=1" (I don't know if it was using llvmpipe or swrast, took halve a minute to render if that says anything).
I'll provide a way to reproduce the issue in a followup comment.