24.4. Sample Shading

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(⌈ minSampleShading × rasterizationSamples ⌉, 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.