VulkanHub

VK_KHR_fragment_shading_rate

Other Extension Metadata

Last Modified Date

2021-09-30

Interactions and External Dependencies
Contributors
  • Tobias Hector, AMD
  • Guennadi Riguer, AMD
  • Matthaeus Chajdas, AMD
  • Pat Brown, Nvidia
  • Matthew Netsch, Qualcomm
  • Slawomir Grajewski, Intel
  • Jan-Harald Fredriksen, Arm
  • Jeff Bolz, Nvidia
  • Arseny Kapoulkine, Roblox
  • Contributors to the VK_NV_shading_rate_image specification
  • Contributors to the VK_EXT_fragment_density_map specification

Description

This extension adds the ability to change the rate at which fragments are shaded. Rather than the usual single fragment invocation for each pixel covered by a primitive, multiple pixels can be shaded by a single fragment shader invocation.

Up to three methods are available to the application to change the fragment shading rate:

Additionally, these rates can all be specified and combined in order to adjust the overall detail in the image at each point.

This functionality can be used to focus shading efforts where higher levels of detail are needed in some parts of a scene compared to others. This can be particularly useful in high resolution rendering, or for XR contexts.

This extension also adds support for the SPV_KHR_fragment_shading_rate extension which enables setting the primitive fragment shading rate, and allows querying the final shading rate from a fragment shader.

New Commands

New Structures

If Vulkan Version 1.3 or VK_KHR_dynamic_rendering is supported:

New Enums

New Enum Constants

  • VK_KHR_FRAGMENT_SHADING_RATE_EXTENSION_NAME
  • VK_KHR_FRAGMENT_SHADING_RATE_SPEC_VERSION
  • Extending VkAccessFlagBits:
    • VK_ACCESS_FRAGMENT_SHADING_RATE_ATTACHMENT_READ_BIT_KHR
  • Extending VkDynamicState:
    • VK_DYNAMIC_STATE_FRAGMENT_SHADING_RATE_KHR
  • Extending VkFormatFeatureFlagBits:
    • VK_FORMAT_FEATURE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR
  • Extending VkImageLayout:
    • VK_IMAGE_LAYOUT_FRAGMENT_SHADING_RATE_ATTACHMENT_OPTIMAL_KHR
  • Extending VkImageUsageFlagBits:
    • VK_IMAGE_USAGE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR
  • Extending VkPipelineStageFlagBits:
    • VK_PIPELINE_STAGE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR
  • Extending VkStructureType:
    • VK_STRUCTURE_TYPE_FRAGMENT_SHADING_RATE_ATTACHMENT_INFO_KHR
    • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FRAGMENT_SHADING_RATE_FEATURES_KHR
    • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FRAGMENT_SHADING_RATE_KHR
    • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FRAGMENT_SHADING_RATE_PROPERTIES_KHR
    • VK_STRUCTURE_TYPE_PIPELINE_FRAGMENT_SHADING_RATE_STATE_CREATE_INFO_KHR

If VK_KHR_format_feature_flags2 or Vulkan Version 1.3 is supported:

If Vulkan Version 1.3 or VK_KHR_dynamic_rendering is supported:

  • Extending VkPipelineCreateFlagBits:
    • VK_PIPELINE_CREATE_RENDERING_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR
    • VK_PIPELINE_RASTERIZATION_STATE_CREATE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR
  • Extending VkStructureType:
    • VK_STRUCTURE_TYPE_RENDERING_FRAGMENT_SHADING_RATE_ATTACHMENT_INFO_KHR

Version History

  • Revision 1, 2020-05-06 (Tobias Hector)
    • Initial revision
  • Revision 2, 2021-09-30 (Jon Leech)