VkBuildAccelerationStructureFlagBitsKHR(3)

C Specification

Bits which can be set in VkAccelerationStructureBuildGeometryInfoKHR::flags or VkAccelerationStructureInfoNV::flags specifying additional parameters for acceleration structure builds, are:

// Provided by VK_KHR_acceleration_structure
typedef enum VkBuildAccelerationStructureFlagBitsKHR {
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_UPDATE_BIT_KHR = 0x00000001,
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_COMPACTION_BIT_KHR = 0x00000002,
    VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_TRACE_BIT_KHR = 0x00000004,
    VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_BUILD_BIT_KHR = 0x00000008,
    VK_BUILD_ACCELERATION_STRUCTURE_LOW_MEMORY_BIT_KHR = 0x00000010,
  // Provided by VK_NV_ray_tracing_motion_blur
    VK_BUILD_ACCELERATION_STRUCTURE_MOTION_BIT_NV = 0x00000020,
  // Provided by VK_EXT_opacity_micromap
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_UPDATE_BIT_EXT = 0x00000040,
  // Provided by VK_EXT_opacity_micromap
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISABLE_OPACITY_MICROMAPS_BIT_EXT = 0x00000080,
  // Provided by VK_EXT_opacity_micromap
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_DATA_UPDATE_BIT_EXT = 0x00000100,
#ifdef VK_ENABLE_BETA_EXTENSIONS
  // Provided by VK_NV_displacement_micromap
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISPLACEMENT_MICROMAP_UPDATE_BIT_NV = 0x00000200,
#endif
  // Provided by VK_KHR_ray_tracing_position_fetch
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DATA_ACCESS_BIT_KHR = 0x00000800,
  // Provided by VK_NV_cluster_acceleration_structure
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_CLUSTER_OPACITY_MICROMAPS_BIT_NV = 0x00001000,
  // Provided by VK_NV_ray_tracing
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_UPDATE_BIT_NV = VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_UPDATE_BIT_KHR,
  // Provided by VK_NV_ray_tracing
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_COMPACTION_BIT_NV = VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_COMPACTION_BIT_KHR,
  // Provided by VK_NV_ray_tracing
    VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_TRACE_BIT_NV = VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_TRACE_BIT_KHR,
  // Provided by VK_NV_ray_tracing
    VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_BUILD_BIT_NV = VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_BUILD_BIT_KHR,
  // Provided by VK_NV_ray_tracing
    VK_BUILD_ACCELERATION_STRUCTURE_LOW_MEMORY_BIT_NV = VK_BUILD_ACCELERATION_STRUCTURE_LOW_MEMORY_BIT_KHR,
  // Provided by VK_EXT_opacity_micromap
  // VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_UPDATE_EXT is a legacy alias
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_UPDATE_EXT = VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_UPDATE_BIT_EXT,
  // Provided by VK_EXT_opacity_micromap
  // VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISABLE_OPACITY_MICROMAPS_EXT is a legacy alias
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISABLE_OPACITY_MICROMAPS_EXT = VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISABLE_OPACITY_MICROMAPS_BIT_EXT,
  // Provided by VK_EXT_opacity_micromap
  // VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_DATA_UPDATE_EXT is a legacy alias
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_DATA_UPDATE_EXT = VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_DATA_UPDATE_BIT_EXT,
#ifdef VK_ENABLE_BETA_EXTENSIONS
  // Provided by VK_NV_displacement_micromap
  // VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISPLACEMENT_MICROMAP_UPDATE_NV is a legacy alias
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISPLACEMENT_MICROMAP_UPDATE_NV = VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISPLACEMENT_MICROMAP_UPDATE_BIT_NV,
#endif
  // Provided by VK_KHR_ray_tracing_position_fetch
  // VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DATA_ACCESS_KHR is a legacy alias
    VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DATA_ACCESS_KHR = VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DATA_ACCESS_BIT_KHR,
} VkBuildAccelerationStructureFlagBitsKHR;

// Provided by VK_NV_ray_tracing
// Equivalent to VkBuildAccelerationStructureFlagBitsKHR
typedef VkBuildAccelerationStructureFlagBitsKHR VkBuildAccelerationStructureFlagBitsNV;

Description

VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_UPDATE_BIT_KHR specifies that the specified acceleration structure can be updated with a mode of VK_BUILD_ACCELERATION_STRUCTURE_MODE_UPDATE_KHR in VkAccelerationStructureBuildGeometryInfoKHR or an update of VK_TRUE in vkCmdBuildAccelerationStructureNV . For sphere and LSS primitives, only positions and radii may be updated, the provided index buffers and flags must remain unchanged from the initial build.
VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_COMPACTION_BIT_KHR specifies that the specified acceleration structure can act as the source for a copy acceleration structure command with mode of VK_COPY_ACCELERATION_STRUCTURE_MODE_COMPACT_KHR to produce a compacted acceleration structure.
VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_TRACE_BIT_KHR specifies that the given acceleration structure build should prioritize trace performance over build time.
VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_BUILD_BIT_KHR specifies that the given acceleration structure build should prioritize build time over trace performance.
VK_BUILD_ACCELERATION_STRUCTURE_LOW_MEMORY_BIT_KHR specifies that this acceleration structure should minimize the size of the scratch memory and the final result acceleration structure, potentially at the expense of build time or trace performance.
VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_UPDATE_BIT_EXT specifies that the opacity micromaps associated with the specified acceleration structure may change with an acceleration structure update.
VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_OPACITY_MICROMAP_DATA_UPDATE_BIT_EXT specifies that the data of the opacity micromaps associated with the specified acceleration structure may change with an acceleration structure update.
VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISABLE_OPACITY_MICROMAPS_BIT_EXT specifies that the specified acceleration structure may be referenced in an instance with VK_GEOMETRY_INSTANCE_DISABLE_OPACITY_MICROMAPS_BIT_EXT set.
VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_CLUSTER_OPACITY_MICROMAPS_BIT_NV specifies that opacity micromaps may be associated with the given cluster acceleration structure.
VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DATA_ACCESS_BIT_KHR specifies that the specified acceleration structure can be used when fetching the vertex and radius positions of a hit LSS or sphere primitive, or vertex positions of a hit triangle.
VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_DISPLACEMENT_MICROMAP_UPDATE_BIT_NV specifies that the displacement micromaps associated with the specified acceleration structure may change with an acceleration structure update.

Note	VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_UPDATE_BIT_KHR and VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_COMPACTION_BIT_KHR may take more time and memory than a normal build, and so should only be used when those features are needed.

Note

VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_UPDATE_BIT_KHR and VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_COMPACTION_BIT_KHR are allowed to be used together. In that case, the result of the compaction copy is used as the source of a build with mode of VK_BUILD_ACCELERATION_STRUCTURE_MODE_UPDATE_KHR to perform the compacted update.

Document Notes

For more information, see the Vulkan Specification.

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright

SPDX-License-Identifier: CC-BY-4.0

VkBuildAccelerationStructureFlagBitsKHR(3) Manual Page

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C Specification

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