VSM light-bleed reduction: remap the Chebyshev probability so everything below
amount clamps to fully shadowed. The over-estimate that washes out the
overlap band between separated occluders lives in the low tail of [0,1], so
cutting it removes the bleed at a small cost in penumbra darkness. amount of
0 disables it.
VSM light-bleed reduction: remap the Chebyshev probability so everything below
amountclamps to fully shadowed. The over-estimate that washes out the overlap band between separated occluders lives in the low tail of [0,1], so cutting it removes the bleed at a small cost in penumbra darkness.amountof 0 disables it.