Sample shading can be used to specify a minimum number of unique samples to
process for each fragment. Sample shading is controlled by the
sampleShadingEnable
member of
VkPipelineMultisampleStateCreateInfo
. If sampleShadingEnable
is
VK_FALSE
, sample shading is considered disabled and has no effect.
Otherwise, an implementation must provide a minimum of
$\max(\lceil{minSampleShading \times rasterizationSamples}\rceil,
1)$
unique associated data for each fragment, where minSampleShading
is the minimum fraction of sample shading and rasterizationSamples
is
the number of samples requested in
VkPipelineMultisampleStateCreateInfo
. These are associated with the
samples in an implementation-dependent manner. When the sample shading
fraction is 1.0, a separate set of associated data are evaluated for each
sample, and each set of values is evaluated at the sample location.