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Structures

VkAccelerationStructureTrianglesOpacityMicromapEXT

Structure specifying an opacity micromap in a bottom-level acceleration structure

The VkAccelerationStructureTrianglesOpacityMicromapEXT structure is defined as:

typedef struct VkAccelerationStructureTrianglesOpacityMicromapEXT {
    VkStructureType sType;
    void* pNext;
    VkIndexType indexType;
    VkDeviceOrHostAddressConstKHR indexBuffer;
    VkDeviceSize indexStride;
    uint32_t baseTriangle;
    uint32_t usageCountsCount;
    const VkMicromapUsageEXT* pUsageCounts;
    const VkMicromapUsageEXT* const* ppUsageCounts;
    VkMicromapEXT micromap;
} VkAccelerationStructureTrianglesOpacityMicromapEXT;
  • sType is a VkStructureType value identifying this structure.
  • pNext is NULL or a pointer to a structure extending this structure.
  • indexType is the type of triangle indices used when indexing this micromap.
  • indexBuffer is a device or host address of memory containing the triangle indices. When indexType is VK_INDEX_TYPE_NONE_KHR it must be NULL.
  • indexStride is the byte stride between triangle indices.
  • baseTriangle is the base value added to the non-negative triangle indices.
  • usageCountsCount specifies the number of usage counts structures that will be used to determine the size of this micromap.
  • pUsageCounts is a pointer to an array of VkMicromapUsageEXT structures.
  • ppUsageCounts is a pointer to an array of pointers to VkMicromapUsageEXT structures.
  • micromap is the handle to the micromap object to include in this geometry.

If VkAccelerationStructureTrianglesOpacityMicromapEXT is included in the pNext chain of a VkAccelerationStructureDenseGeometryFormatTrianglesDataAMDX or VkAccelerationStructureGeometryTrianglesDataKHR structure, that geometry will reference that micromap.

For each triangle in the geometry, the acceleration structure build fetches an index from indexBuffer using indexType and indexStride if present. If indexType is VK_INDEX_TYPE_NONE_KHR, then the index used is the index of the triangle in the geometry.

If that value is the unsigned cast of one of the values from VkOpacityMicromapSpecialIndexEXT then that triangle behaves as described for that special value in Ray Opacity Micromap.

Otherwise that triangle uses the opacity micromap information from micromap at that index plus baseTriangle.

Only one of pUsageCounts or ppUsageCounts can be a valid pointer, the other must be NULL. The elements of the non-NULL array describe the total count used to build this geometry. For a given format and subdivisionLevel the number of triangles in this geometry matching those values after indirection and special index handling must be equal to the sum of matching count provided.

If micromap is VK_NULL_HANDLE, then every value read from indexBuffer must be one of the values in VkOpacityMicromapSpecialIndexEXT.

Valid Usage

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-pUsageCounts-07335

Only one of pUsageCounts or ppUsageCounts can be a valid pointer, the other must be NULL

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-indexType-10719

indexType must be VK_INDEX_TYPE_UINT16, VK_INDEX_TYPE_UINT32, or VK_INDEX_TYPE_NONE_KHR

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-indexType-10722

If indexType is not VK_INDEX_TYPE_NONE_KHR, then indexStride must be a multiple of the size in bytes of indexType

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-indexType-10723

If indexType is not VK_INDEX_TYPE_NONE_KHR, then indexStride must be less than or equal to 232-1

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-format-11679

If micromap is not VK_NULL_HANDLE, the type used to construct micromap is VK_MICROMAP_TYPE_OPACITY_MICROMAP_EXT, the format member of each element of pUsageCounts or ppUsageCounts must be a valid value from VkOpacityMicromapFormatEXT

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-subdivisionLevel-11680

If micromap is not VK_NULL_HANDLE, the type used to build micromap is VK_MICROMAP_TYPE_OPACITY_MICROMAP_EXT, for each member of pUsageCounts or ppUsageCounts with format equal to VK_OPACITY_MICROMAP_FORMAT_2_STATE_EXT, subdivisionLevel must be less than or equal to [VkPhysicalDeviceOpacityMicromapPropertiesEXT::maxOpacity2StateSubdivisionLevel](xref::limits-maxOpacity2StateSubdivisionLevelEXT)

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-subdivisionLevel-11681

If micromap is not VK_NULL_HANDLE, the type used to build micromap is VK_MICROMAP_TYPE_OPACITY_MICROMAP_EXT, for each member of pUsageCounts or ppUsageCounts with format equal to VK_OPACITY_MICROMAP_FORMAT_4_STATE_EXT, subdivisionLevel must be less than or equal to [VkPhysicalDeviceOpacityMicromapPropertiesEXT::maxOpacity4StateSubdivisionLevel](xref::limits-maxOpacity4StateSubdivisionLevelEXT)

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-format-11682

If micromap is not VK_NULL_HANDLE, the type used to construct micromap is VK_MICROMAP_TYPE_DISPLACEMENT_MICROMAP_NV, the format member of each element of pUsageCounts or ppUsageCounts must be a valid value from VkDisplacementMicromapFormatNV

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-subdivisionLevel-11683

If micromap is not VK_NULL_HANDLE, the type used to construct micromap is VK_MICROMAP_TYPE_DISPLACEMENT_MICROMAP_NV, for each member of pUsageCounts or ppUsageCounts subdivisionLevel must be less than or equal to VkPhysicalDeviceDisplacementMicromapPropertiesNV::maxDisplacementMicromapSubdivisionLevel

Valid Usage (Implicit)

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-sType-sType

sType must be VK_STRUCTURE_TYPE_ACCELERATION_STRUCTURE_TRIANGLES_OPACITY_MICROMAP_EXT

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-indexType-parameter

indexType must be a valid VkIndexType value

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-pUsageCounts-parameter

If usageCountsCount is not 0, and pUsageCounts is not NULL, pUsageCounts must be a valid pointer to an array of usageCountsCount VkMicromapUsageEXT structures

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-ppUsageCounts-parameter

If usageCountsCount is not 0, and ppUsageCounts is not NULL, ppUsageCounts must be a valid pointer to an array of usageCountsCount valid pointers to VkMicromapUsageEXT structures

VUID-VkAccelerationStructureTrianglesOpacityMicromapEXT-micromap-parameter

If micromap is not VK_NULL_HANDLE, micromap must be a valid VkMicromapEXT handle