As a test, I rendered
the image with
QMC GI instead of
irradiance map for
first bounce. QMC
GI is not an ap-
proximate method like IR map with
its undersampling
algorithm. QMC GI
calculates the GI
without compromise,
every light sample
gets equal attention.
So it’s a good test to
compare how well
the GI with IR map is
computed.
As you can see,
in the areas with
much lighting detail,
the QMC GI image
looks better (more
physically correct)
than the IR map
image. But it takes
10 minutes com-
pared to 1 minute 24
seconds for the IR
map version... If you
want more detailed
GI with IR map, you
need to edit some of
the IR map settings.