C Specification
The VkAccelerationStructureTrianglesOpacityMicromapEXT structure is
defined as:
// Provided by VK_EXT_opacity_micromap
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;
Members
-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
indexTypeis the type of triangle indices used when indexing this micromap -
indexBufferis the address containing the triangle indices -
indexStrideis the byte stride between triangle indices -
baseTriangleis the base value added to the non-negative triangle indices -
usageCountsCountspecifies the number of usage counts structures that will be used to determine the size of this micromap. -
pUsageCountsis a pointer to an array of VkMicromapUsageEXT structures. -
ppUsageCountsis a pointer to an array of pointers to VkMicromapUsageEXT structures. -
micromapis the handle to the micromap object to include in this geometry
Description
If VkAccelerationStructureTrianglesOpacityMicromapEXT is included in
the pNext chain of a
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 indexBuffer is NULL 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.
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.